261775964849687 has 2 divisors, whose sum is σ = 261775964849688. Its totient is φ = 261775964849686.

The previous prime is 261775964849627. The next prime is 261775964849797. The reversal of 261775964849687 is 786948469577162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261775964849687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261775964849627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130887982424843 + 130887982424844.

It is an arithmetic number, because the mean of its divisors is an integer number (130887982424844).

Almost surely, 2^{261775964849687} is an apocalyptic number.

261775964849687 is a deficient number, since it is larger than the sum of its proper divisors (1).

261775964849687 is an equidigital number, since it uses as much as digits as its factorization.

261775964849687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61451550720, while the sum is 89.

The spelling of 261775964849687 in words is "two hundred sixty-one trillion, seven hundred seventy-five billion, nine hundred sixty-four million, eight hundred forty-nine thousand, six hundred eighty-seven".