399309624 has 384 divisors, whose sum is σ = 1422720000. Its totient is φ = 100590336.

The previous prime is 399309607. The next prime is 399309641. The reversal of 399309624 is 426903993.

It is an interprime number because it is at equal distance from previous prime (399309607) and next prime (399309641).

It is a self number, because there is not a number n which added to its sum of digits gives 399309624.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10792134 + ... + 10792170.

It is an arithmetic number, because the mean of its divisors is an integer number (3705000).

Almost surely, 2^399309624 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 399309624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (711360000).

399309624 is an abundant number, since it is smaller than the sum of its proper divisors (1023410376).

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

399309624 is a wasteful number, since it uses less digits than its factorization.

399309624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 91 counting only the distinct ones).

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

The square root of 399309624 is about 19982.7331463942. The cubic root of 399309624 is about 736.3821611335.

The spelling of 399309624 in words is "three hundred ninety-nine million, three hundred nine thousand, six hundred twenty-four".