391662920 has 128 divisors (see below), whose sum is σ = 997539840. Its totient is φ = 137168640.

The previous prime is 391662913. The next prime is 391662937. The reversal of 391662920 is 29266193.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2402759 + ... + 2402921.

It is an arithmetic number, because the mean of its divisors is an integer number (7793280).

Almost surely, 2^391662920 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 391662920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (498769920).

391662920 is an abundant number, since it is smaller than the sum of its proper divisors (605876920).

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

391662920 is a wasteful number, since it uses less digits than its factorization.

391662920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 391662920 is about 19790.4754869609. The cubic root of 391662920 is about 731.6513065466.

The spelling of 391662920 in words is "three hundred ninety-one million, six hundred sixty-two thousand, nine hundred twenty".