399021734756736 has 1280 divisors, whose sum is σ = 1467907322112000. Its totient is φ = 104777581363200.

The previous prime is 399021734756693. The next prime is 399021734756737. The reversal of 399021734756736 is 637657437120993.

399021734756736 is a `hidden beast` number, since 3 + 9 + 9 + 0 + 2 + 17 + 3 + 47 + 567 + 3 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399021734756737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 285219252165 + ... + 285219253563.

It is an arithmetic number, because the mean of its divisors is an integer number (1146802595400).

Almost surely, 2^{399021734756736} is an apocalyptic number.

399021734756736 is a gapful number since it is divisible by the number (36) 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 399021734756736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (733953661056000).

399021734756736 is an abundant number, since it is smaller than the sum of its proper divisors (1068885587355264).

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

399021734756736 is a wasteful number, since it uses less digits than its factorization.

399021734756736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2549 (or 2528 counting only the distinct ones).

The product of its (nonzero) digits is 1080203040, while the sum is 72.

The spelling of 399021734756736 in words is "three hundred ninety-nine trillion, twenty-one billion, seven hundred thirty-four million, seven hundred fifty-six thousand, seven hundred thirty-six".