399907643968 has 28 divisors (see below), whose sum is σ = 906933407872. Its totient is φ = 171388990080.

The previous prime is 399907643963. The next prime is 399907644007. The reversal of 399907643968 is 869346709993.

It is a tau number, because it is divible by the number of its divisors (28).

It is a super-2 number, since 2×399907643968² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 399907643968.

It is not an unprimeable number, because it can be changed into a prime (399907643963) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 446325048 + ... + 446325943.

Almost surely, 2^399907643968 is an apocalyptic number.

It is an amenable number.

399907643968 is an abundant number, since it is smaller than the sum of its proper divisors (507025763904).

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

399907643968 is an equidigital number, since it uses as much as digits as its factorization.

399907643968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892651010 (or 892651000 counting only the distinct ones).

The product of its (nonzero) digits is 476171136, while the sum is 73.

The spelling of 399907643968 in words is "three hundred ninety-nine billion, nine hundred seven million, six hundred forty-three thousand, nine hundred sixty-eight".