21872364 has 24 divisors (see below), whose sum is σ = 51179520. Its totient is φ = 7270224.

The previous prime is 21872341. The next prime is 21872369. The reversal of 21872364 is 46327812.

It is not an unprimeable number, because it can be changed into a prime (21872369) 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, 2217 + ... + 6975.

It is an arithmetic number, because the mean of its divisors is an integer number (2132480).

Almost surely, 2^21872364 is an apocalyptic number.

It is an amenable number.

21872364 is an abundant number, since it is smaller than the sum of its proper divisors (29307156).

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

21872364 is a wasteful number, since it uses less digits than its factorization.

21872364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5149 (or 5147 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 21872364 is about 4676.7899247240. The cubic root of 21872364 is about 279.6610013013.

The spelling of 21872364 in words is "twenty-one million, eight hundred seventy-two thousand, three hundred sixty-four".