391984380 has 48 divisors (see below), whose sum is σ = 1219508640. Its totient is φ = 104529024.

The previous prime is 391984363. The next prime is 391984393. The reversal of 391984380 is 83489193.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 362409 + ... + 363488.

It is an arithmetic number, because the mean of its divisors is an integer number (25406430).

Almost surely, 2^391984380 is an apocalyptic number.

391984380 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

391984380 is an abundant number, since it is smaller than the sum of its proper divisors (827524260).

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

391984380 is a wasteful number, since it uses less digits than its factorization.

391984380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725915 (or 725907 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 391984380 is about 19798.5954047251. The cubic root of 391984380 is about 731.8514210668.

The spelling of 391984380 in words is "three hundred ninety-one million, nine hundred eighty-four thousand, three hundred eighty".