866772172036 has 27 divisors (see below), whose sum is σ = 1532969591349. Its totient is φ = 428828811648.

The previous prime is 866772171971. The next prime is 866772172043. The reversal of 866772172036 is 630271277668.

The square root of 866772172036 is 931006.

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., 389213776900 + 477558395136 = 623870^2 + 691056^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 180612765 + ... + 180617563.

Almost surely, 2^866772172036 is an apocalyptic number.

866772172036 is the 931006-th square number.

It is an amenable number.

866772172036 is a deficient number, since it is larger than the sum of its proper divisors (666197419313).

866772172036 is an frugal number, since it uses more digits than its factorization.

866772172036 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9796 (or 4898 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 55.

The spelling of 866772172036 in words is "eight hundred sixty-six billion, seven hundred seventy-two million, one hundred seventy-two thousand, thirty-six".