399939624 has 96 divisors (see below), whose sum is σ = 1241136000. Its totient is φ = 113970816.

The previous prime is 399939577. The next prime is 399939647. The reversal of 399939624 is 426939993.

399939624 is a `hidden beast` number, since 3 + 9 + 9 + 9 + 3 + 9 + 624 = 666.

It is a super-2 number, since 2×399939624² = 319903405690522752, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 255757 + ... + 257315.

It is an arithmetic number, because the mean of its divisors is an integer number (12928500).

Almost surely, 2^399939624 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399939624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (620568000).

399939624 is an abundant number, since it is smaller than the sum of its proper divisors (841196376).

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

399939624 is a wasteful number, since it uses less digits than its factorization.

399939624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2087 (or 2080 counting only the distinct ones).

The product of its digits is 2834352, while the sum is 54.

The square root of 399939624 is about 19998.4905430385. The cubic root of 399939624 is about 736.7692266818.

The spelling of 399939624 in words is "three hundred ninety-nine million, nine hundred thirty-nine thousand, six hundred twenty-four".