399651928 has 64 divisors (see below), whose sum is σ = 870357600. Its totient is φ = 170449920.

The previous prime is 399651913. The next prime is 399651937. The reversal of 399651928 is 829156993.

It is a Harshad number since it is a multiple of its sum of digits (52).

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, 78550 + ... + 83482.

Almost surely, 2^399651928 is an apocalyptic number.

399651928 is a gapful number since it is divisible by the number (38) 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 399651928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435178800).

399651928 is an abundant number, since it is smaller than the sum of its proper divisors (470705672).

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

399651928 is a wasteful number, since it uses less digits than its factorization.

399651928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5012 (or 5008 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 52.

The square root of 399651928 is about 19991.2963061428. The cubic root of 399651928 is about 736.5925196717.

The spelling of 399651928 in words is "three hundred ninety-nine million, six hundred fifty-one thousand, nine hundred twenty-eight".