399370321 has 16 divisors (see below), whose sum is σ = 476872704. Its totient is φ = 327018384.

The previous prime is 399370319. The next prime is 399370333. The reversal of 399370321 is 123073993.

It is not a de Polignac number, because 399370321 - 2¹ = 399370319 is a prime.

It is not an unprimeable number, because it can be changed into a prime (399370921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 251496 + ... + 253078.

It is an arithmetic number, because the mean of its divisors is an integer number (29804544).

Almost surely, 2^399370321 is an apocalyptic number.

It is an amenable number.

399370321 is a deficient number, since it is larger than the sum of its proper divisors (77502383).

399370321 is a wasteful number, since it uses less digits than its factorization.

399370321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3180.

The product of its (nonzero) digits is 30618, while the sum is 37.

The square root of 399370321 is about 19984.2518248745. The cubic root of 399370321 is about 736.4194704635.

The spelling of 399370321 in words is "three hundred ninety-nine million, three hundred seventy thousand, three hundred twenty-one".