261647574717361 has 4 divisors (see below), whose sum is σ = 299025799676992. Its totient is φ = 224269349757732.

The previous prime is 261647574717349. The next prime is 261647574717371. The reversal of 261647574717361 is 163717475746162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261647574717361 - 2²¹ = 261647572620209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261647574717371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18689112479805 + ... + 18689112479818.

It is an arithmetic number, because the mean of its divisors is an integer number (74756449919248).

Almost surely, 2^{261647574717361} is an apocalyptic number.

It is an amenable number.

261647574717361 is a deficient number, since it is larger than the sum of its proper divisors (37378224959631).

261647574717361 is an equidigital number, since it uses as much as digits as its factorization.

261647574717361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37378224959630.

The product of its digits is 248935680, while the sum is 67.

The spelling of 261647574717361 in words is "two hundred sixty-one trillion, six hundred forty-seven billion, five hundred seventy-four million, seven hundred seventeen thousand, three hundred sixty-one".