399020791680 has 512 divisors, whose sum is σ = 1617501312000. Its totient is φ = 91068309504.

The previous prime is 399020791657. The next prime is 399020791717. The reversal of 399020791680 is 86197020993.

399020791680 is a `hidden beast` number, since 399 + 0 + 20 + 79 + 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, 96403051 + ... + 96407189.

It is an arithmetic number, because the mean of its divisors is an integer number (3159182250).

Almost surely, 2^399020791680 is an apocalyptic number.

399020791680 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 399020791680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (808750656000).

399020791680 is an abundant number, since it is smaller than the sum of its proper divisors (1218480520320).

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

399020791680 is a wasteful number, since it uses less digits than its factorization.

399020791680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4971 (or 4953 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 399020791680 in words is "three hundred ninety-nine billion, twenty million, seven hundred ninety-one thousand, six hundred eighty".