391666842 has 48 divisors (see below), whose sum is σ = 1026896832. Its totient is φ = 105321600.

The previous prime is 391666819. The next prime is 391666843. The reversal of 391666842 is 248666193.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (391666843) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89284 + ... + 93567.

It is an arithmetic number, because the mean of its divisors is an integer number (21393684).

Almost surely, 2^391666842 is an apocalyptic number.

391666842 is an abundant number, since it is smaller than the sum of its proper divisors (635229990).

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

391666842 is a wasteful number, since it uses less digits than its factorization.

391666842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182883 (or 182880 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 391666842 is about 19790.5745747818. The cubic root of 391666842 is about 731.6537487205.

The spelling of 391666842 in words is "three hundred ninety-one million, six hundred sixty-six thousand, eight hundred forty-two".