21672912 has 20 divisors (see below), whose sum is σ = 55988480. Its totient is φ = 7224288.

The previous prime is 21672907. The next prime is 21672913. The reversal of 21672912 is 21927612.

It is a super-2 number, since 2×21672912² = 939430229119488, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21672912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21672913) 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, 225712 + ... + 225807.

It is an arithmetic number, because the mean of its divisors is an integer number (2799424).

Almost surely, 2^21672912 is an apocalyptic number.

It is an amenable number.

21672912 is an abundant number, since it is smaller than the sum of its proper divisors (34315568).

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

21672912 is a wasteful number, since it uses less digits than its factorization.

21672912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451530 (or 451524 counting only the distinct ones).

The product of its digits is 3024, while the sum is 30.

The square root of 21672912 is about 4655.4174893343. The cubic root of 21672912 is about 278.8083369093.

The spelling of 21672912 in words is "twenty-one million, six hundred seventy-two thousand, nine hundred twelve".