399371728 has 20 divisors (see below), whose sum is σ = 884323360. Its totient is φ = 171159264.

The previous prime is 399371723. The next prime is 399371771. The reversal of 399371728 is 827173993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399371723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1782798 + ... + 1783021.

It is an arithmetic number, because the mean of its divisors is an integer number (44216168).

Almost surely, 2^399371728 is an apocalyptic number.

It is an amenable number.

399371728 is an abundant number, since it is smaller than the sum of its proper divisors (484951632).

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

399371728 is a wasteful number, since it uses less digits than its factorization.

399371728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3565834 (or 3565828 counting only the distinct ones).

The product of its digits is 571536, while the sum is 49.

The square root of 399371728 is about 19984.2870275624. The cubic root of 399371728 is about 736.4203352757.

The spelling of 399371728 in words is "three hundred ninety-nine million, three hundred seventy-one thousand, seven hundred twenty-eight".