866788526244961 has 2 divisors, whose sum is σ = 866788526244962. Its totient is φ = 866788526244960.

The previous prime is 866788526244947. The next prime is 866788526245007. The reversal of 866788526244961 is 169442625887668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 547117548615936 + 319670977629025 = 23390544^2 + 17879345^2 .

It is a cyclic number.

It is not a de Polignac number, because 866788526244961 - 2²⁵ = 866788492690529 is a prime.

It is a super-2 number, since 2×866788526244961² (a number of 31 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (866788526244931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433394263122480 + 433394263122481.

It is an arithmetic number, because the mean of its divisors is an integer number (433394263122481).

Almost surely, 2^{866788526244961} is an apocalyptic number.

It is an amenable number.

866788526244961 is a deficient number, since it is larger than the sum of its proper divisors (1).

866788526244961 is an equidigital number, since it uses as much as digits as its factorization.

866788526244961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13377208320, while the sum is 82.

The spelling of 866788526244961 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, five hundred twenty-six million, two hundred forty-four thousand, nine hundred sixty-one".