399937393 has 4 divisors (see below), whose sum is σ = 423463140. Its totient is φ = 376411648.

The previous prime is 399937379. The next prime is 399937423. The reversal of 399937393 is 393739993.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 334780209 + 65157184 = 18297^2 + 8072^2 .

It is a cyclic number.

It is not a de Polignac number, because 399937393 - 2⁹ = 399936881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399937093) 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, 11762848 + ... + 11762881.

It is an arithmetic number, because the mean of its divisors is an integer number (105865785).

Almost surely, 2^399937393 is an apocalyptic number.

It is an amenable number.

399937393 is a deficient number, since it is larger than the sum of its proper divisors (23525747).

399937393 is a wasteful number, since it uses less digits than its factorization.

399937393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23525746.

The product of its digits is 3720087, while the sum is 55.

The square root of 399937393 is about 19998.4347637509. The cubic root of 399937393 is about 736.7678566957.

The spelling of 399937393 in words is "three hundred ninety-nine million, nine hundred thirty-seven thousand, three hundred ninety-three".