399616128 has 96 divisors (see below), whose sum is σ = 1164758400. Its totient is φ = 131489280.

The previous prime is 399616109. The next prime is 399616153. The reversal of 399616128 is 821616993.

It is a happy number.

399616128 is a `hidden beast` number, since 3 + 9 + 9 + 616 + 1 + 28 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88813 + ... + 93203.

It is an arithmetic number, because the mean of its divisors is an integer number (12132900).

Almost surely, 2^399616128 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 399616128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (582379200).

399616128 is an abundant number, since it is smaller than the sum of its proper divisors (765142272).

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

399616128 is a wasteful number, since it uses less digits than its factorization.

399616128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4490 (or 4475 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 399616128 is about 19990.4008964303. The cubic root of 399616128 is about 736.5705248659.

The spelling of 399616128 in words is "three hundred ninety-nine million, six hundred sixteen thousand, one hundred twenty-eight".