261665714621255 has 32 divisors (see below), whose sum is σ = 381263424474240. Its totient is φ = 168558566561280.

The previous prime is 261665714621209. The next prime is 261665714621263. The reversal of 261665714621255 is 552126417566162.

It is not a de Polignac number, because 261665714621255 - 2²² = 261665710426951 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261665714621194 and 261665714621203.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 3483729116 + ... + 3483804225.

It is an arithmetic number, because the mean of its divisors is an integer number (11914482014820).

Almost surely, 2^{261665714621255} is an apocalyptic number.

261665714621255 is a deficient number, since it is larger than the sum of its proper divisors (119597709852985).

261665714621255 is a wasteful number, since it uses less digits than its factorization.

261665714621255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6967533419.

The product of its digits is 36288000, while the sum is 59.

The spelling of 261665714621255 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, seven hundred fourteen million, six hundred twenty-one thousand, two hundred fifty-five".