261616631155 has 8 divisors (see below), whose sum is σ = 342479953584. Its totient is φ = 190266640800.

The previous prime is 261616631123. The next prime is 261616631167. The reversal of 261616631155 is 551136616162.

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

It is not a de Polignac number, because 261616631155 - 2⁵ = 261616631123 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2378332956 + ... + 2378333065.

It is an arithmetic number, because the mean of its divisors is an integer number (42809994198).

Almost surely, 2^261616631155 is an apocalyptic number.

261616631155 is a deficient number, since it is larger than the sum of its proper divisors (80863322429).

261616631155 is a wasteful number, since it uses less digits than its factorization.

261616631155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4756666037.

The product of its digits is 194400, while the sum is 43.

The spelling of 261616631155 in words is "two hundred sixty-one billion, six hundred sixteen million, six hundred thirty-one thousand, one hundred fifty-five".