399604320 has 192 divisors, whose sum is σ = 1408155840. Its totient is φ = 105836544.

The previous prime is 399604301. The next prime is 399604321. The reversal of 399604320 is 23406993.

It is a happy number.

It is a super-2 number, since 2×399604320² = 319367225125324800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399604321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1006362 + ... + 1006758.

It is an arithmetic number, because the mean of its divisors is an integer number (7334145).

Almost surely, 2^399604320 is an apocalyptic number.

399604320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 399604320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (704077920).

399604320 is an abundant number, since it is smaller than the sum of its proper divisors (1008551520).

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

399604320 is a wasteful number, since it uses less digits than its factorization.

399604320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654 (or 640 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The square root of 399604320 is about 19990.1055524977. The cubic root of 399604320 is about 736.5632699782.

The spelling of 399604320 in words is "three hundred ninety-nine million, six hundred four thousand, three hundred twenty".