399794640 has 80 divisors (see below), whose sum is σ = 1416421248. Its totient is φ = 91381248.

The previous prime is 399794639. The next prime is 399794677. The reversal of 399794640 is 46497993.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-3 number, since 3×399794640³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117307 + ... + 120666.

Almost surely, 2^399794640 is an apocalyptic number.

399794640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

399794640 is an abundant number, since it is smaller than the sum of its proper divisors (1016626608).

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

399794640 is a wasteful number, since it uses less digits than its factorization.

399794640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237996 (or 237990 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 51.

The square root of 399794640 is about 19994.8653408819. The cubic root of 399794640 is about 736.6801860253.

The spelling of 399794640 in words is "three hundred ninety-nine million, seven hundred ninety-four thousand, six hundred forty".