391971982 has 16 divisors (see below), whose sum is σ = 598525200. Its totient is φ = 192491392.

The previous prime is 391971973. The next prime is 391971989. The reversal of 391971982 is 289179193.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391971989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21894 + ... + 35542.

It is an arithmetic number, because the mean of its divisors is an integer number (37407825).

Almost surely, 2^391971982 is an apocalyptic number.

391971982 is a deficient number, since it is larger than the sum of its proper divisors (206553218).

391971982 is a wasteful number, since it uses less digits than its factorization.

391971982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13907.

The product of its digits is 244944, while the sum is 49.

The square root of 391971982 is about 19798.2822992299. The cubic root of 391971982 is about 731.8437051219.

The spelling of 391971982 in words is "three hundred ninety-one million, nine hundred seventy-one thousand, nine hundred eighty-two".