21058256 has 40 divisors (see below), whose sum is σ = 42747264. Its totient is φ = 10039040.

The previous prime is 21058249. The next prime is 21058259. The reversal of 21058256 is 65285012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21058259) 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, 30491 + ... + 31173.

Almost surely, 2^21058256 is an apocalyptic number.

It is an amenable number.

21058256 is an abundant number, since it is smaller than the sum of its proper divisors (21689008).

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

21058256 is a wasteful number, since it uses less digits than its factorization.

21058256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779 (or 773 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 21058256 is about 4588.9275435552. The cubic root of 21058256 is about 276.1472993751.

The spelling of 21058256 in words is "twenty-one million, fifty-eight thousand, two hundred fifty-six".