390991218 has 16 divisors (see below), whose sum is σ = 782935680. Its totient is φ = 130171536.

The previous prime is 390991207. The next prime is 390991241. The reversal of 390991218 is 812199093.

It is a self number, because there is not a number n which added to its sum of digits gives 390991218.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34330 + ... + 44277.

It is an arithmetic number, because the mean of its divisors is an integer number (48933480).

Almost surely, 2^390991218 is an apocalyptic number.

390991218 is an abundant number, since it is smaller than the sum of its proper divisors (391944462).

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

390991218 is a wasteful number, since it uses less digits than its factorization.

390991218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79441.

The product of its (nonzero) digits is 34992, while the sum is 42.

The square root of 390991218 is about 19773.4978696234. The cubic root of 390991218 is about 731.2328064918.

The spelling of 390991218 in words is "three hundred ninety million, nine hundred ninety-one thousand, two hundred eighteen".