391691388 has 24 divisors (see below), whose sum is σ = 997032960. Its totient is φ = 118694320.

The previous prime is 391691381. The next prime is 391691389. The reversal of 391691388 is 883196193.

It is a hoax number, since the sum of its digits (48) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391691381) 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 7 ways as a sum of consecutive naturals, for example, 1483548 + ... + 1483811.

It is an arithmetic number, because the mean of its divisors is an integer number (41543040).

Almost surely, 2^391691388 is an apocalyptic number.

It is an amenable number.

391691388 is an abundant number, since it is smaller than the sum of its proper divisors (605341572).

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

391691388 is a wasteful number, since it uses less digits than its factorization.

391691388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2967377 (or 2967375 counting only the distinct ones).

The product of its digits is 279936, while the sum is 48.

The square root of 391691388 is about 19791.1947087587. The cubic root of 391691388 is about 731.6690327968.

The spelling of 391691388 in words is "three hundred ninety-one million, six hundred ninety-one thousand, three hundred eighty-eight".