399719764821 has 96 divisors (see below), whose sum is σ = 614555811840. Its totient is φ = 230337499392.

The previous prime is 399719764793. The next prime is 399719764849. The reversal of 399719764821 is 128467917993.

It is an interprime number because it is at equal distance from previous prime (399719764793) and next prime (399719764849).

It is not a de Polignac number, because 399719764821 - 2⁶ = 399719764757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399719764121) 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 95 ways as a sum of consecutive naturals, for example, 485685816 + ... + 485686638.

It is an arithmetic number, because the mean of its divisors is an integer number (6401623040).

Almost surely, 2^399719764821 is an apocalyptic number.

It is an amenable number.

399719764821 is a deficient number, since it is larger than the sum of its proper divisors (214836047019).

399719764821 is a wasteful number, since it uses less digits than its factorization.

399719764821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395 (or 1382 counting only the distinct ones).

The product of its digits is 41150592, while the sum is 66.

The spelling of 399719764821 in words is "three hundred ninety-nine billion, seven hundred nineteen million, seven hundred sixty-four thousand, eight hundred twenty-one".