666734568394 has 24 divisors (see below), whose sum is σ = 1035901054188. Its totient is φ = 321833406720.

The previous prime is 666734568389. The next prime is 666734568419. The reversal of 666734568394 is 493865437666.

It can be written as a sum of positive squares in 6 ways, for example, as 544208667025 + 122525901369 = 737705^2 + 350037^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18249954 + ... + 18286450.

Almost surely, 2^666734568394 is an apocalyptic number.

666734568394 is a deficient number, since it is larger than the sum of its proper divisors (369166485794).

666734568394 is a wasteful number, since it uses less digits than its factorization.

666734568394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47418 (or 47389 counting only the distinct ones).

The product of its digits is 470292480, while the sum is 67.

The spelling of 666734568394 in words is "six hundred sixty-six billion, seven hundred thirty-four million, five hundred sixty-eight thousand, three hundred ninety-four".