261266178317 has 2 divisors, whose sum is σ = 261266178318. Its totient is φ = 261266178316.

The previous prime is 261266178307. The next prime is 261266178353. The reversal of 261266178317 is 713871662162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 226025127241 + 35241051076 = 475421^2 + 187726^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261266178317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261266178307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130633089158 + 130633089159.

It is an arithmetic number, because the mean of its divisors is an integer number (130633089159).

Almost surely, 2^261266178317 is an apocalyptic number.

It is an amenable number.

261266178317 is a deficient number, since it is larger than the sum of its proper divisors (1).

261266178317 is an equidigital number, since it uses as much as digits as its factorization.

261266178317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1016064, while the sum is 50.

The spelling of 261266178317 in words is "two hundred sixty-one billion, two hundred sixty-six million, one hundred seventy-eight thousand, three hundred seventeen".