399944524336821 has 8 divisors (see below), whose sum is σ = 592510406424960. Its totient is φ = 266629682891196.

The previous prime is 399944524336733. The next prime is 399944524336871. The reversal of 399944524336821 is 128633425449993.

399944524336821 is a `hidden beast` number, since 3 + 9 + 9 + 9 + 4 + 4 + 524 + 33 + 68 + 2 + 1 = 666.

It is not a de Polignac number, because 399944524336821 - 2²⁹ = 399943987465909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399944524336821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399944524336871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7406380080285 + ... + 7406380080338.

It is an arithmetic number, because the mean of its divisors is an integer number (74063800803120).

Almost surely, 2^{399944524336821} is an apocalyptic number.

It is an amenable number.

399944524336821 is a deficient number, since it is larger than the sum of its proper divisors (192565882088139).

399944524336821 is a wasteful number, since it uses less digits than its factorization.

399944524336821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14812760160632 (or 14812760160626 counting only the distinct ones).

The product of its digits is 1209323520, while the sum is 72.

The spelling of 399944524336821 in words is "three hundred ninety-nine trillion, nine hundred forty-four billion, five hundred twenty-four million, three hundred thirty-six thousand, eight hundred twenty-one".