We tend to think of odd numbers as male and even numbers as female.

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This ancient belief was tested by James Wilkie and Galen Bodenhausen of Northwestern University. In his latest book, Alex Bellos writes: "They showed respondents randomly assigned pictures of the faces of young babies, each next to a three-digit number that was either odd-odd-odd or even-even-even, and asked them to guess the baby’s sex [...] Respondents were about 10 per cent more likely to say that a baby paired with odd numbers was a boy, than if the same baby was paired with even numbers."

. If you shuffle a pack of cards properly, chances are that exact order has never been seen before in the whole history of the universe.

Via giphy.com

Proof.

 Zero is an even number.

daizuoxin / Thinkstock

But people take longer to decide whether it's even or odd because it's not as easy for us to mentally categorise.

 There's not enough space in the known universe to write out a googolplex on paper.

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According to Carl Sagan in the original Cosmos series. A googolplex is 10 to the power of a googol, or 10 to the power of 10 to the power of 100. This website will write it out for you (or start... it won't ever finish because your computer won't have enough memory).

The most popular favourite number is 7.

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Flickr: losmininos / Creative Commons

Nearly 3000 people, around 10% of the total asked, chose 7 as their favourite number in an online poll by Alex Bellos. The second most popular was 3.

That might be because 7 is "arithmetically unique".

Flickr: pagedooley / Creative Commons

It's the only number below 10 you can't multiply or divide and keep within group. For example, 5 you can multiply by 2 to get 10 (still within the 1-10 group), 6 and 8 you can divide by 2.

17. 7 also shows up a lot in human culture.

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We have seven deadly sins, and seven wonders of the world. Not to mention colours of the rainbow, pillars of wisdom, seas, dwarves, days in the week...

This might be because when these things came about there were celestial bodies visible in the sky (the Sun, the Moon, Venus, Mercury, Mars, Jupiter and Saturn).

18. The number 4 is considered unlucky in much of Asia.

Flickr: boklm / Creative Commons

That's because the words for "four" in Japanese, Cantonese, Mandarin and Korean (shi, sei, si, sa) sound the same as the words in those languages for death.

19. .999999... = 1

Flickr: andrec / Creative Commons

Here's the proof:

If 10N = 9.9999...

Then N = .9999....

Subtract N from 10N, leaving you with 9N=9.

So then N=1. But we already know that N=.9999... as well.

So 1=.9999....

20. Cicadas use prime numbers as an evolutionary strategy.

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Flickr: oakleyoriginals / Creative Commons

Cicadas incubate underground for long periods of time – 13 or 17 years – before coming out to mate. 13 and 17 are both prime numbers. It's thought cicadas ended up in these prime number life-cycles because it meant they came into contact with predators on more round numbered life-cycles less often.

1. Zero ( 0 ) is the only number which can not be represented by Roman numerals.

 2. What comes after a million, billion and trillion? A quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion and undecillion 

3. Plus (+) and Minus (-) sign symbols were used as early as 1489 A.D 

4. 2 and 5 are the only primes that end in 2 or 5 

5. An icosagon is a shape with 20 sides 

. Among all shapes with the same perimeter a circle has the largest area. 

. Among all shapes with the same area circle has the shortest perimeter 

. 40 when written "forty" is the only number with letters in alphabetical order, while "one" is the only one with letters in reverse order

. 'FOUR' is the only number in the English language that is spelt with the same number of letters as the number itself

 . From 0 to 1,000, the letter "A" only appears in 1,000 ("one thousand") 

11. 12,345,678,987,654,321 is the product of 111,111,111 x 111,111,111. Notice the sequence of the numbers 1 to 9 and back to 1. 

12. Have you ever noticed that the opposite sides a die always add up to seven (7) 

13. Trigonometry is the study of the relationship between the angles of triangles and their sides 

14. Abacus is considered the origin of the calculator 

15. Here is an interesting trick to check divisibility of any number by number 3.A number is divisible by three if the sum of its digits is divisible by three (3) 

16. Do you know the magic of no. nine (9)? Multiply any number with nine (9 ) and then sum all individual digits of the result (product) to make it single digit, the sum of all these individual digits would always be nine (9). 

17. If you add up the numbers 1-100 consecutively (1+2+3+4+5...) the total is 5050 

18. A 'jiffy' is an actual unit of time for 1/100th of a second 

19. Have you heard about a Palindrome Number? It is a number that reads the same backwards and forward, e.g. 12421 

20. Have you heard about Fibonacci? It is the sequence of numbers wherein a number is the result of adding the two numbers before it! Here is an example: 1, 1, 2, 3, 5, 8, 13, 21, 34, and so on 

10! seconds is exactly 6 weeks.

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10! means 10 factorial. 10! = 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 3628800 seconds. Which is 42 days, or 6 weeks, exactly.

22. Take any four digit number, follow these steps, and you'll end up with 6174.

stevanovicigor / BuzzFeed

1. Choose a four digit number (the only condition is that it has at least two different digits).

2. Arrange the digits of the four digit number in descending then ascending order.

3. Subtract the smaller number from the bigger one.

4. Repeat.

Eventually you'll end up at 6174, which is known as Kaprekar's constant. If you then repeat the process you'll just keep getting 6174 over and over again.

23. 555 is used by some in Thailand as slang for "hahaha", because the word for "five" is pronounced "ha".

TO MAKE OUR POINT, LET'S CHECK OUT A FEW INTERESTING FACTS ABOUT MATHEMATICS:

1. GOOGLE IS ALL ABOUT MATHEMATICS

The lifeline of today's time, Google, derived its name from the word 'googol' -- a mathematical term for the number 1 followed by 100 zeros, which reflect infinite amount of search on the internet.

2. CRAZY MULTIPLICATIONS

A very interesting things about math is how crazy it gets with its function. For instance, if you multiply 111,111,111 by 111,111,111, this becomes equal to 12,345,678,987,654,321.

3. THE TERMINOLOGY DILEMMA

This debate is going on for a long time now. But the answer depends on which part of the world you are in. Americans called mathematics 'math', saying that the function of the same is a singular noun and with that logic, they prefer saying 'math', which is singular too. On the other hand, speakers of British English would always say 'maths', as in 'I have a degree in maths'.

However, there are logical arguments for both the spellings. The Oxford and the Merriam-Webster dictionaries say the word is plural because of the letter 's' in the end. On the contrary however, it is usually used as a singular noun. For example, 'Mathematics is my favourite subject' and not 'Mathematics are my favourite subject'.

Other plural nouns that are used as if they were singular are economics, ethics, politics, gymnastics, measles and dominoes. These words, however, are not habitually shortened, making math/maths rather an unusual word.

4. DREADFULLY LONG DIVISION

Another mind-boggling application of maths comes in when the number 1 is divided by 998,001. The answer would give you a complete sequence from 000 to 999 in order. Don't agree with us? Go ahead and try it, and be ready to waste one entire notebook!

5. PIZZA AND MATH: ARE THEY RELATED?

We may seem like someone who is ruining pizza for you but you will be amazed to know its relation with maths. To find out the volume of the cylindrical shape of the pizza, the formula used is Pi x r² x h.

So, if an ordinary pizza has a radius of 'z' and height 'a', its volume is Pi x z x z x a which makes up 'pizza'.

6. MAGICAL DIGIT!

The number 9 is believed to be a magical number with certain very interesting properties. This is because if you multiply a number with 9, and add all the digits of the resulting number, the sum would always come out to be 9.

7. ZERO IS NOT THERE IN ROMAN NUMERALS

Did you know that one of the most important numbers, zero, is not represented in the Roman numerals? Derived from the Arabic word, 'sifr', it is known from a variety of other names like naught, zip, nil and zilch.

8. DID SHAKESPEARE TOO HAVE ISSUES WITH MATHS?

No don't get us wrong, Shakespeare was a literature lover and not a math lover, but the only time he included the word 'mathematics' was in his play, The Taming of the Shrew.

9. WHAT COMES AFTER A MILLION?

After a million comes--- billion, trillion, quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion, and undecillion.

10. THE GROWTH OF OUR MATHEMATICAL KNOWLEDGE

In 1900, all the world's mathematical knowledge could be written in 80 books; today it would fill more than 1,00,000 books.