391157904 has 20 divisors (see below), whose sum is σ = 1010491376. Its totient is φ = 130385952.

The previous prime is 391157903. The next prime is 391157933. The reversal of 391157904 is 409751193.

It is a happy number.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (391157903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4074514 + ... + 4074609.

Almost surely, 2^391157904 is an apocalyptic number.

It is an amenable number.

391157904 is an abundant number, since it is smaller than the sum of its proper divisors (619333472).

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

391157904 is a wasteful number, since it uses less digits than its factorization.

391157904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8149134 (or 8149128 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 391157904 is about 19777.7123045109. The cubic root of 391157904 is about 731.3367039276.

It can be divided in two parts, 39 and 1157904, that multiplied together give a triangular number (45158256 = T₉₅₀₃).

The spelling of 391157904 in words is "three hundred ninety-one million, one hundred fifty-seven thousand, nine hundred four".