21338256 has 20 divisors (see below), whose sum is σ = 55123952. Its totient is φ = 7112736.

The previous prime is 21338243. The next prime is 21338257. The reversal of 21338256 is 65283312.

It is not an unprimeable number, because it can be changed into a prime (21338257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222226 + ... + 222321.

Almost surely, 2^21338256 is an apocalyptic number.

It is an amenable number.

21338256 is an abundant number, since it is smaller than the sum of its proper divisors (33785696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21338256 is a wasteful number, since it uses less digits than its factorization.

21338256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444558 (or 444552 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 21338256 is about 4619.3350170777. The cubic root of 21338256 is about 277.3658405149.

The spelling of 21338256 in words is "twenty-one million, three hundred thirty-eight thousand, two hundred fifty-six".