21039372 has 24 divisors (see below), whose sum is σ = 54546800. Its totient is φ = 7013088.

The previous prime is 21039371. The next prime is 21039373. The reversal of 21039372 is 27393012.

It is an interprime number because it is at equal distance from previous prime (21039371) and next prime (21039373).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21039371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97297 + ... + 97512.

Almost surely, 2^21039372 is an apocalyptic number.

It is an amenable number.

21039372 is an abundant number, since it is smaller than the sum of its proper divisors (33507428).

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

21039372 is a wasteful number, since it uses less digits than its factorization.

21039372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194822 (or 194814 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 21039372 is about 4586.8695207080. The cubic root of 21039372 is about 276.0647296194.

The spelling of 21039372 in words is "twenty-one million, thirty-nine thousand, three hundred seventy-two".