21279272 has 32 divisors (see below), whose sum is σ = 47174400. Its totient is φ = 8804544.

The previous prime is 21279263. The next prime is 21279283. The reversal of 21279272 is 27297212.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

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, 4928 + ... + 8175.

It is an arithmetic number, because the mean of its divisors is an integer number (1474200).

Almost surely, 2^21279272 is an apocalyptic number.

It is an amenable number.

21279272 is an abundant number, since it is smaller than the sum of its proper divisors (25895128).

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

21279272 is a wasteful number, since it uses less digits than its factorization.

21279272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13145 (or 13141 counting only the distinct ones).

The product of its digits is 7056, while the sum is 32.

The square root of 21279272 is about 4612.9461301862. The cubic root of 21279272 is about 277.1100363484.

The spelling of 21279272 in words is "twenty-one million, two hundred seventy-nine thousand, two hundred seventy-two".