261544475653617 has 8 divisors (see below), whose sum is σ = 375551041964224. Its totient is φ = 160950446556048.

The previous prime is 261544475653561. The next prime is 261544475653661. The reversal of 261544475653617 is 716356574445162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261544475653617 - 2³⁵ = 261510115915249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261544475653687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3353134303213 + ... + 3353134303290.

It is an arithmetic number, because the mean of its divisors is an integer number (46943880245528).

Almost surely, 2^{261544475653617} is an apocalyptic number.

It is an amenable number.

261544475653617 is a deficient number, since it is larger than the sum of its proper divisors (114006566310607).

261544475653617 is a wasteful number, since it uses less digits than its factorization.

261544475653617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6706268606519.

The product of its digits is 508032000, while the sum is 66.

The spelling of 261544475653617 in words is "two hundred sixty-one trillion, five hundred forty-four billion, four hundred seventy-five million, six hundred fifty-three thousand, six hundred seventeen".