399257315728 has 20 divisors (see below), whose sum is σ = 773612356300. Its totient is φ = 199615417344.

The previous prime is 399257315711. The next prime is 399257315759. The reversal of 399257315728 is 827513752993.

It can be written as a sum of positive squares in 2 ways, for example, as 265134367744 + 134122947984 = 514912^2 + 366228^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 576453 + ... + 1063396.

It is an arithmetic number, because the mean of its divisors is an integer number (38680617815).

Almost surely, 2^399257315728 is an apocalyptic number.

It is an amenable number.

399257315728 is a deficient number, since it is larger than the sum of its proper divisors (374355040572).

399257315728 is a wasteful number, since it uses less digits than its factorization.

399257315728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655074 (or 1655068 counting only the distinct ones).

The product of its digits is 28576800, while the sum is 61.

The spelling of 399257315728 in words is "three hundred ninety-nine billion, two hundred fifty-seven million, three hundred fifteen thousand, seven hundred twenty-eight".