866513772276656 has 80 divisors (see below), whose sum is σ = 1951532218944000. Its totient is φ = 365012129823744.

The previous prime is 866513772276637. The next prime is 866513772276661. The reversal of 866513772276656 is 656672277315668.

It is a super-2 number, since 2×866513772276656² (a number of 31 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32448221 + ... + 52781763.

It is an arithmetic number, because the mean of its divisors is an integer number (24394152736800).

Almost surely, 2^{866513772276656} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 866513772276656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975766109472000).

866513772276656 is an abundant number, since it is smaller than the sum of its proper divisors (1085018446667344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

866513772276656 is a wasteful number, since it uses less digits than its factorization.

866513772276656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20340066 (or 20340060 counting only the distinct ones).

The product of its digits is 6401203200, while the sum is 77.

The spelling of 866513772276656 in words is "eight hundred sixty-six trillion, five hundred thirteen billion, seven hundred seventy-two million, two hundred seventy-six thousand, six hundred fifty-six".