261553771606271 has 8 divisors (see below), whose sum is σ = 261820756224000. Its totient is φ = 261286825537440.

The previous prime is 261553771606219. The next prime is 261553771606277. The reversal of 261553771606271 is 172606177355162.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261553771606271 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 261553771606271.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261553771606277) 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 7 ways as a sum of consecutive naturals, for example, 3949445 + ... + 23210033.

It is an arithmetic number, because the mean of its divisors is an integer number (32727594528000).

Almost surely, 2^{261553771606271} is an apocalyptic number.

261553771606271 is a deficient number, since it is larger than the sum of its proper divisors (266984617729).

261553771606271 is a wasteful number, since it uses less digits than its factorization.

261553771606271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19274449.

The product of its (nonzero) digits is 22226400, while the sum is 59.

The spelling of 261553771606271 in words is "two hundred sixty-one trillion, five hundred fifty-three billion, seven hundred seventy-one million, six hundred six thousand, two hundred seventy-one".