666517156672 has 14 divisors (see below), whose sum is σ = 1322619982898. Its totient is φ = 333258578304.

The previous prime is 666517156667. The next prime is 666517156681. The reversal of 666517156672 is 276651715666.

It can be written as a sum of positive squares in only one way, i.e., 613126584576 + 53390572096 = 783024^2 + 231064^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5207165223 + ... + 5207165350.

Almost surely, 2^666517156672 is an apocalyptic number.

It is an amenable number.

666517156672 is a deficient number, since it is larger than the sum of its proper divisors (656102826226).

666517156672 is a wasteful number, since it uses less digits than its factorization.

666517156672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10414330585 (or 10414330575 counting only the distinct ones).

The product of its digits is 19051200, while the sum is 58.

The spelling of 666517156672 in words is "six hundred sixty-six billion, five hundred seventeen million, one hundred fifty-six thousand, six hundred seventy-two".