668511187761 has 32 divisors (see below), whose sum is σ = 932170643712. Its totient is φ = 425749975040.

The previous prime is 668511187711. The next prime is 668511187763. The reversal of 668511187761 is 167781115866.

It is a cyclic number.

It is not a de Polignac number, because 668511187761 - 2⁷ = 668511187633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (668511187763) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3177121 + ... + 3380993.

It is an arithmetic number, because the mean of its divisors is an integer number (29130332616).

Almost surely, 2^668511187761 is an apocalyptic number.

It is an amenable number.

668511187761 is a deficient number, since it is larger than the sum of its proper divisors (263659455951).

668511187761 is a wasteful number, since it uses less digits than its factorization.

668511187761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204473.

The product of its digits is 3386880, while the sum is 57.

The spelling of 668511187761 in words is "six hundred sixty-eight billion, five hundred eleven million, one hundred eighty-seven thousand, seven hundred sixty-one".