399131953920 has 864 divisors, whose sum is σ = 1700979517440. Its totient is φ = 88275640320.

The previous prime is 399131953901. The next prime is 399131953963. The reversal of 399131953920 is 29359131993.

399131953920 is a `hidden beast` number, since 3 + 9 + 91 + 3 + 19 + 539 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 52492839 + ... + 52500441.

Almost surely, 2^399131953920 is an apocalyptic number.

399131953920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399131953920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850489758720).

399131953920 is an abundant number, since it is smaller than the sum of its proper divisors (1301847563520).

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

399131953920 is a wasteful number, since it uses less digits than its factorization.

399131953920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7678 (or 7651 counting only the distinct ones).

The product of its (nonzero) digits is 1771470, while the sum is 54.

The spelling of 399131953920 in words is "three hundred ninety-nine billion, one hundred thirty-one million, nine hundred fifty-three thousand, nine hundred twenty".