21265804 has 18 divisors (see below), whose sum is σ = 43291500. Its totient is φ = 9113832.

The previous prime is 21265789. The next prime is 21265817. The reversal of 21265804 is 40856212.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 54054 + ... + 54445.

Almost surely, 2^21265804 is an apocalyptic number.

It is an amenable number.

21265804 is an abundant number, since it is smaller than the sum of its proper divisors (22025696).

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

21265804 is a wasteful number, since it uses less digits than its factorization.

21265804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108517 (or 108508 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 21265804 is about 4611.4860945253. The cubic root of 21265804 is about 277.0515615155.

The spelling of 21265804 in words is "twenty-one million, two hundred sixty-five thousand, eight hundred four".