393939665 has 24 divisors (see below), whose sum is σ = 561624192. Its totient is φ = 264374880.

The previous prime is 393939587. The next prime is 393939677. The reversal of 393939665 is 566939393.

It is a happy number.

393939665 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 393939665 - 2⁸ = 393939409 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5591 + ... + 28620.

It is an arithmetic number, because the mean of its divisors is an integer number (23401008).

Almost surely, 2^393939665 is an apocalyptic number.

393939665 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

393939665 is a deficient number, since it is larger than the sum of its proper divisors (167684527).

393939665 is a wasteful number, since it uses less digits than its factorization.

393939665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34277 (or 34270 counting only the distinct ones).

The product of its digits is 3542940, while the sum is 53.

The square root of 393939665 is about 19847.9133663970. The cubic root of 393939665 is about 733.0662699480.

The spelling of 393939665 in words is "three hundred ninety-three million, nine hundred thirty-nine thousand, six hundred sixty-five".