866513772276401 has 2 divisors, whose sum is σ = 866513772276402. Its totient is φ = 866513772276400.

The previous prime is 866513772276343. The next prime is 866513772276407. The reversal of 866513772276401 is 104672277315668.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 531529520645776 + 334984251630625 = 23054924^2 + 18302575^2 .

It is a cyclic number.

It is not a de Polignac number, because 866513772276401 - 2²² = 866513768082097 is a prime.

It is a super-2 number, since 2×866513772276401² (a number of 31 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (866513772276407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433256886138200 + 433256886138201.

It is an arithmetic number, because the mean of its divisors is an integer number (433256886138201).

Almost surely, 2^{866513772276401} is an apocalyptic number.

It is an amenable number.

866513772276401 is a deficient number, since it is larger than the sum of its proper divisors (1).

866513772276401 is an equidigital number, since it uses as much as digits as its factorization.

866513772276401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 142248960, while the sum is 65.

The spelling of 866513772276401 in words is "eight hundred sixty-six trillion, five hundred thirteen billion, seven hundred seventy-two million, two hundred seventy-six thousand, four hundred one".