261545262723155 has 4 divisors (see below), whose sum is σ = 313854315267792. Its totient is φ = 209236210178520.

The previous prime is 261545262723131. The next prime is 261545262723161. The reversal of 261545262723155 is 551327262545162.

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

It is not a de Polignac number, because 261545262723155 - 2¹⁴ = 261545262706771 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261545262723155.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26154526272311 + ... + 26154526272320.

It is an arithmetic number, because the mean of its divisors is an integer number (78463578816948).

Almost surely, 2^{261545262723155} is an apocalyptic number.

261545262723155 is a deficient number, since it is larger than the sum of its proper divisors (52309052544637).

261545262723155 is an equidigital number, since it uses as much as digits as its factorization.

261545262723155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52309052544636.

The product of its digits is 30240000, while the sum is 56.

The spelling of 261545262723155 in words is "two hundred sixty-one trillion, five hundred forty-five billion, two hundred sixty-two million, seven hundred twenty-three thousand, one hundred fifty-five".