399623136 has 96 divisors (see below), whose sum is σ = 1150184448. Its totient is φ = 120483840.

The previous prime is 399623129. The next prime is 399623141. The reversal of 399623136 is 631326993.

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

Its product of digits (157464) is a multiple of the sum of its prime factors (1944).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234640 + ... + 236336.

It is an arithmetic number, because the mean of its divisors is an integer number (11981088).

Almost surely, 2^399623136 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 399623136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (575092224).

399623136 is an abundant number, since it is smaller than the sum of its proper divisors (750561312).

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

399623136 is a wasteful number, since it uses less digits than its factorization.

399623136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1944 (or 1936 counting only the distinct ones).

The product of its digits is 157464, while the sum is 42.

The square root of 399623136 is about 19990.5761797903. The cubic root of 399623136 is about 736.5748305447.

The spelling of 399623136 in words is "three hundred ninety-nine million, six hundred twenty-three thousand, one hundred thirty-six".