21465256 has 32 divisors (see below), whose sum is σ = 42989760. Its totient is φ = 10023552.

The previous prime is 21465253. The next prime is 21465289. The reversal of 21465256 is 65256412.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21465251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6556 + ... + 9268.

It is an arithmetic number, because the mean of its divisors is an integer number (1343430).

Almost surely, 2^21465256 is an apocalyptic number.

It is an amenable number.

21465256 is an abundant number, since it is smaller than the sum of its proper divisors (21524504).

21465256 is a wasteful number, since it uses less digits than its factorization.

21465256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2785 (or 2781 counting only the distinct ones).

The product of its digits is 14400, while the sum is 31.

The square root of 21465256 is about 4633.0611910485. The cubic root of 21465256 is about 277.9150232832.

The spelling of 21465256 in words is "twenty-one million, four hundred sixty-five thousand, two hundred fifty-six".