399640003920 has 60 divisors (see below), whose sum is σ = 1342124348916. Its totient is φ = 106570667520.

The previous prime is 399640003909. The next prime is 399640004003. The reversal of 399640003920 is 29300046993.

It can be written as a sum of positive squares in 2 ways, for example, as 265525845264 + 134114158656 = 515292^2 + 366216^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 277527061 + ... + 277528500.

Almost surely, 2^399640003920 is an apocalyptic number.

399640003920 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399640003920 is an abundant number, since it is smaller than the sum of its proper divisors (942484344996).

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

399640003920 is a wasteful number, since it uses less digits than its factorization.

399640003920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555055580 (or 555055571 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 45.

The spelling of 399640003920 in words is "three hundred ninety-nine billion, six hundred forty million, three thousand, nine hundred twenty".