215865172 has 12 divisors (see below), whose sum is σ = 385801920. Its totient is φ = 105636056.

The previous prime is 215865163. The next prime is 215865173. The reversal of 215865172 is 271568512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215865173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 573922 + ... + 574297.

It is an arithmetic number, because the mean of its divisors is an integer number (32150160).

Almost surely, 2^215865172 is an apocalyptic number.

It is an amenable number.

215865172 is a deficient number, since it is larger than the sum of its proper divisors (169936748).

215865172 is a wasteful number, since it uses less digits than its factorization.

215865172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1148270 (or 1148268 counting only the distinct ones).

The product of its digits is 33600, while the sum is 37.

The square root of 215865172 is about 14692.3507989702. The cubic root of 215865172 is about 599.8751332749.

The spelling of 215865172 in words is "two hundred fifteen million, eight hundred sixty-five thousand, one hundred seventy-two".