261611111163 has 4 divisors (see below), whose sum is σ = 348814814888. Its totient is φ = 174407407440.

The previous prime is 261611111161. The next prime is 261611111221. The reversal of 261611111163 is 361111116162.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 261611111163 - 2¹ = 261611111161 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 261611111163.

It is not an unprimeable number, because it can be changed into a prime (261611111161) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 43601851858 + ... + 43601851863.

It is an arithmetic number, because the mean of its divisors is an integer number (87203703722).

Almost surely, 2^261611111163 is an apocalyptic number.

261611111163 is a deficient number, since it is larger than the sum of its proper divisors (87203703725).

261611111163 is an equidigital number, since it uses as much as digits as its factorization.

261611111163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87203703724.

The product of its digits is 1296, while the sum is 30.

The spelling of 261611111163 in words is "two hundred sixty-one billion, six hundred eleven million, one hundred eleven thousand, one hundred sixty-three".