391087172 has 24 divisors (see below), whose sum is σ = 785460480. Its totient is φ = 166904640.

The previous prime is 391087171. The next prime is 391087181. The reversal of 391087172 is 271780193.

It is a super-2 number, since 2×391087172² = 305898352205915168, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (391087171) 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 7 ways as a sum of consecutive naturals, for example, 22529 + ... + 35912.

It is an arithmetic number, because the mean of its divisors is an integer number (32727520).

Almost surely, 2^391087172 is an apocalyptic number.

It is an amenable number.

391087172 is an abundant number, since it is smaller than the sum of its proper divisors (394373308).

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

391087172 is a wasteful number, since it uses less digits than its factorization.

391087172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58691 (or 58689 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 391087172 is about 19775.9240492069. The cubic root of 391087172 is about 731.2926194070.

The spelling of 391087172 in words is "three hundred ninety-one million, eighty-seven thousand, one hundred seventy-two".