399987328 has 64 divisors (see below), whose sum is σ = 862283520. Its totient is φ = 183720960.

The previous prime is 399987323. The next prime is 399987383. The reversal of 399987328 is 823789993.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (399987323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 450501 + ... + 451387.

It is an arithmetic number, because the mean of its divisors is an integer number (13473180).

Almost surely, 2^399987328 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 399987328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (431141760).

399987328 is an abundant number, since it is smaller than the sum of its proper divisors (462296192).

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

399987328 is a wasteful number, since it uses less digits than its factorization.

399987328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1185 (or 1173 counting only the distinct ones).

The product of its digits is 5878656, while the sum is 58.

The square root of 399987328 is about 19999.6831974909. The cubic root of 399987328 is about 736.7985189714.

The spelling of 399987328 in words is "three hundred ninety-nine million, nine hundred eighty-seven thousand, three hundred twenty-eight".