261775964849759 has 4 divisors (see below), whose sum is σ = 262466666604360. Its totient is φ = 261085263095160.

The previous prime is 261775964849687. The next prime is 261775964849797. The reversal of 261775964849759 is 957948469577162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261775964849759 - 2²⁴ = 261775948072543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261775964840759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 345350876732 + ... + 345350877489.

It is an arithmetic number, because the mean of its divisors is an integer number (65616666651090).

Almost surely, 2^{261775964849759} is an apocalyptic number.

261775964849759 is a deficient number, since it is larger than the sum of its proper divisors (690701754601).

261775964849759 is an equidigital number, since it uses as much as digits as its factorization.

261775964849759 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690701754600.

The product of its digits is 57610828800, while the sum is 89.

The spelling of 261775964849759 in words is "two hundred sixty-one trillion, seven hundred seventy-five billion, nine hundred sixty-four million, eight hundred forty-nine thousand, seven hundred fifty-nine".