66505264565776 has 15 divisors (see below), whose sum is σ = 128854013298061. Its totient is φ = 33252615972736.

The previous prime is 66505264565759. The next prime is 66505264565797. The reversal of 66505264565776 is 67756546250566.

The square root of 66505264565776 is 8155076.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 52668054940176 + 13837209625600 = 7257276^2 + 3719840^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 31600920 + ... + 33639688.

Almost surely, 2^{66505264565776} is an apocalyptic number.

66505264565776 is the 8155076-th square number.

It is an amenable number.

66505264565776 is a deficient number, since it is larger than the sum of its proper divisors (62348748732285).

66505264565776 is an frugal number, since it uses more digits than its factorization.

66505264565776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4077546 (or 2038771 counting only the distinct ones).

The product of its (nonzero) digits is 1905120000, while the sum is 70.

The spelling of 66505264565776 in words is "sixty-six trillion, five hundred five billion, two hundred sixty-four million, five hundred sixty-five thousand, seven hundred seventy-six".