399326431680 has 448 divisors, whose sum is σ = 1545453043200. Its totient is φ = 96261488640.

The previous prime is 399326431661. The next prime is 399326431703. The reversal of 399326431680 is 86134623993.

399326431680 is a `hidden beast` number, since 399 + 32 + 64 + 3 + 168 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 17000424 + ... + 17023896.

Almost surely, 2^399326431680 is an apocalyptic number.

399326431680 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 399326431680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (772726521600).

399326431680 is an abundant number, since it is smaller than the sum of its proper divisors (1146126611520).

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

399326431680 is a wasteful number, since it uses less digits than its factorization.

399326431680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23689 (or 23673 counting only the distinct ones).

The product of its (nonzero) digits is 5038848, while the sum is 54.

The spelling of 399326431680 in words is "three hundred ninety-nine billion, three hundred twenty-six million, four hundred thirty-one thousand, six hundred eighty".