Across
- 2. If 2k – 1 is a prime number, where k is a prime number, then 2k-1 (2k – 1) is a ________ number.
- 4. ________’s number is a famous irrational denoted by ‘e’. The first few digits of this number look like 2. 71182818284590452353…
- 5. |x| is also known as the ________ of x. (apart from absolute value).
- 6. Two positive integers are said to be _________ numbers if each of them is equal to the sum of all natural divisors excluding the number itself.
Down
- 1. The Golden ratio is an example of ____________ irrational number.
- 3. A rational number has a _____________ decimal expansion, if its denominator can be expressed as 2m* 5n, where m and n are whole numbers.