261266178553 has 16 divisors (see below), whose sum is σ = 269659722240. Its totient is φ = 252944427456.

The previous prime is 261266178521. The next prime is 261266178581. The reversal of 261266178553 is 355871662162.

It is a cyclic number.

It is not a de Polignac number, because 261266178553 - 2⁵ = 261266178521 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 261266178553.

It is not an unprimeable number, because it can be changed into a prime (261266178583) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12077575 + ... + 12099187.

It is an arithmetic number, because the mean of its divisors is an integer number (16853732640).

Almost surely, 2^261266178553 is an apocalyptic number.

It is an amenable number.

261266178553 is a deficient number, since it is larger than the sum of its proper divisors (8393543687).

261266178553 is a wasteful number, since it uses less digits than its factorization.

261266178553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23256.

The product of its digits is 3628800, while the sum is 52.

The spelling of 261266178553 in words is "two hundred sixty-one billion, two hundred sixty-six million, one hundred seventy-eight thousand, five hundred fifty-three".