394593521522 has 6 divisors (see below), whose sum is σ = 591891614829. Its totient is φ = 197296316580.

The previous prime is 394593521521. The next prime is 394593521563. The reversal of 394593521522 is 225125395493.

It can be written as a sum of positive squares in 2 ways, for example, as 226795965361 + 167797556161 = 476231^2 + 409631^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=444181.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (394593521521) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 666272 + ... + 1110452.

Almost surely, 2^394593521522 is an apocalyptic number.

394593521522 is a deficient number, since it is larger than the sum of its proper divisors (197298093307).

394593521522 is an frugal number, since it uses more digits than its factorization.

394593521522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888364 (or 444183 counting only the distinct ones).

The product of its digits is 2916000, while the sum is 50.

Multiplying 394593521522 by its sum of digits (50), we get a square (19729676076100 = 4441810²).

The spelling of 394593521522 in words is "three hundred ninety-four billion, five hundred ninety-three million, five hundred twenty-one thousand, five hundred twenty-two".