15321972 has 24 divisors (see below), whose sum is σ = 36088416. Its totient is φ = 5059168.

The previous prime is 15321949. The next prime is 15321989. The reversal of 15321972 is 27912351.

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 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, 4683 + ... + 7250.

It is an arithmetic number, because the mean of its divisors is an integer number (1503684).

Almost surely, 2^15321972 is an apocalyptic number.

15321972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

15321972 is an abundant number, since it is smaller than the sum of its proper divisors (20766444).

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

15321972 is a wasteful number, since it uses less digits than its factorization.

15321972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12047 (or 12045 counting only the distinct ones).

The product of its digits is 3780, while the sum is 30.

The square root of 15321972 is about 3914.3290612824. The cubic root of 15321972 is about 248.3732888680.

The spelling of 15321972 in words is "fifteen million, three hundred twenty-one thousand, nine hundred seventy-two".