391499868 has 72 divisors (see below), whose sum is σ = 999943056. Its totient is φ = 118801920.

The previous prime is 391499833. The next prime is 391499897. The reversal of 391499868 is 868994193.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 195046 + ... + 197042.

It is an arithmetic number, because the mean of its divisors is an integer number (13888098).

Almost surely, 2^391499868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391499868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (499971528).

391499868 is an abundant number, since it is smaller than the sum of its proper divisors (608443188).

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

391499868 is a wasteful number, since it uses less digits than its factorization.

391499868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2083 (or 2050 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 57.

The square root of 391499868 is about 19786.3556017777. The cubic root of 391499868 is about 731.5497619434.

The spelling of 391499868 in words is "three hundred ninety-one million, four hundred ninety-nine thousand, eight hundred sixty-eight".