666512606321 has 16 divisors (see below), whose sum is σ = 714891355200. Its totient is φ = 619572096000.

The previous prime is 666512606297. The next prime is 666512606327. The reversal of 666512606321 is 123606215666.

It is a cyclic number.

It is not a de Polignac number, because 666512606321 - 2³⁸ = 391634699377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (666512606327) 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, 1282880 + ... + 1725921.

It is an arithmetic number, because the mean of its divisors is an integer number (44680709700).

Almost surely, 2^666512606321 is an apocalyptic number.

It is an amenable number.

666512606321 is a deficient number, since it is larger than the sum of its proper divisors (48378748879).

666512606321 is a wasteful number, since it uses less digits than its factorization.

666512606321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3009040.

The product of its (nonzero) digits is 466560, while the sum is 44.

The spelling of 666512606321 in words is "six hundred sixty-six billion, five hundred twelve million, six hundred six thousand, three hundred twenty-one".