668743974681 has 16 divisors (see below), whose sum is σ = 942240148800. Its totient is φ = 420721164288.

The previous prime is 668743974641. The next prime is 668743974763. The reversal of 668743974681 is 186479347866.

It is not a de Polignac number, because 668743974681 - 2⁶ = 668743974617 is a prime.

It is a super-2 number, since 2×668743974681² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (668743974611) 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, 22810936 + ... + 22840233.

It is an arithmetic number, because the mean of its divisors is an integer number (58890009300).

Almost surely, 2^668743974681 is an apocalyptic number.

It is an amenable number.

668743974681 is a deficient number, since it is larger than the sum of its proper divisors (273496174119).

668743974681 is a wasteful number, since it uses less digits than its factorization.

668743974681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45651448.

The product of its digits is 292626432, while the sum is 69.

The spelling of 668743974681 in words is "six hundred sixty-eight billion, seven hundred forty-three million, nine hundred seventy-four thousand, six hundred eighty-one".