21265264 has 40 divisors (see below), whose sum is σ = 42497280. Its totient is φ = 10304448.

The previous prime is 21265259. The next prime is 21265273. The reversal of 21265264 is 46256212.

It is a super-2 number, since 2×21265264² = 904422905979392, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88857 + ... + 89095.

It is an arithmetic number, because the mean of its divisors is an integer number (1062432).

Almost surely, 2^21265264 is an apocalyptic number.

It is an amenable number.

21265264 is a deficient number, since it is larger than the sum of its proper divisors (21232016).

21265264 is a wasteful number, since it uses less digits than its factorization.

21265264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 391 counting only the distinct ones).

The product of its digits is 5760, while the sum is 28.

The square root of 21265264 is about 4611.4275446981. The cubic root of 21265264 is about 277.0492164500.

The spelling of 21265264 in words is "twenty-one million, two hundred sixty-five thousand, two hundred sixty-four".