393840993 has 16 divisors (see below), whose sum is σ = 646303616. Its totient is φ = 207740160.

The previous prime is 393840973. The next prime is 393841003. The reversal of 393840993 is 399048393.

It is not a de Polignac number, because 393840993 - 2⁸ = 393840737 is a prime.

It is a super-2 number, since 2×393840993² = 310221455534452098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (393840973) 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, 721048 + ... + 721593.

It is an arithmetic number, because the mean of its divisors is an integer number (40393976).

Almost surely, 2^393840993 is an apocalyptic number.

It is an amenable number.

393840993 is a deficient number, since it is larger than the sum of its proper divisors (252462623).

393840993 is a wasteful number, since it uses less digits than its factorization.

393840993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1442664.

The product of its (nonzero) digits is 629856, while the sum is 48.

The square root of 393840993 is about 19845.4275086227. The cubic root of 393840993 is about 733.0050599359.

The spelling of 393840993 in words is "three hundred ninety-three million, eight hundred forty thousand, nine hundred ninety-three".