Number Gossip
(Enter a number and I'll tell you everything you wanted to know about it but were afraid to ask.)
Unique Properties of 251
- 251 is the smallest prime which is an anagram is a cube (actually it is an anagram of two cubes: 125 and 512
- 251 is the smallest prime with digital product equal to ten
- 251 is the smallest number that can be written as the sum of 3 positive cubes in 2 ways: 251 = 23 + 33 + 63 = 13 + 53 + 53
Common Properties of 251
The number n is called an apocalyptic power if 2n contains the consecutive digits 666 (in decimal).
The number n is deficient if the sum of all its positive divisors except itself is less than n.
Compare with perfect and abundant numbers.
A number is odd if it is not divisible by 2.
Numbers that are not odd are even. Compare with another pair -- evil and odious numbers.
The number n is odious if it has an odd number of 1's in its binary expansion.
Guess what evil numbers are.
A prime is a positive integer greater than 1 that is divisible by no positive integers other than 1 and itself.
Prime numbers are opposite to composite numbers.
A number is said to be square-free if its prime decomposition contains no repeated factors.