15555972 has 12 divisors (see below), whose sum is σ = 36297296. Its totient is φ = 5185320.

The previous prime is 15555971. The next prime is 15555973. The reversal of 15555972 is 27955551.

It is an interprime number because it is at equal distance from previous prime (15555971) and next prime (15555973).

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 15555972.

It is not an unprimeable number, because it can be changed into a prime (15555971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 648154 + ... + 648177.

Almost surely, 2^15555972 is an apocalyptic number.

15555972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

15555972 is an abundant number, since it is smaller than the sum of its proper divisors (20741324).

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

15555972 is a wasteful number, since it uses less digits than its factorization.

15555972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1296338 (or 1296336 counting only the distinct ones).

The product of its digits is 78750, while the sum is 39.

The square root of 15555972 is about 3944.1059823489. The cubic root of 15555972 is about 249.6313071964.

The spelling of 15555972 in words is "fifteen million, five hundred fifty-five thousand, nine hundred seventy-two".