390404493 has 6 divisors (see below), whose sum is σ = 563917614. Its totient is φ = 260269656.

The previous prime is 390404479. The next prime is 390404551. The reversal of 390404493 is 394404093.

It can be written as a sum of positive squares in only one way, i.e., 388957284 + 1447209 = 19722^2 + 1203^2 .

It is not a de Polignac number, because 390404493 - 2¹⁷ = 390273421 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (390404393) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21689130 + ... + 21689147.

It is an arithmetic number, because the mean of its divisors is an integer number (93986269).

Almost surely, 2^390404493 is an apocalyptic number.

It is an amenable number.

390404493 is a deficient number, since it is larger than the sum of its proper divisors (173513121).

390404493 is a wasteful number, since it uses less digits than its factorization.

390404493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43378283 (or 43378280 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 390404493 is about 19758.6561536963. The cubic root of 390404493 is about 730.8668585019.

The spelling of 390404493 in words is "three hundred ninety million, four hundred four thousand, four hundred ninety-three".