261005216131 has 16 divisors (see below), whose sum is σ = 296063336448. Its totient is φ = 227947233600.

The previous prime is 261005216123. The next prime is 261005216149. The reversal of 261005216131 is 131612500162.

261005216131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 261005216131 - 2³ = 261005216123 is a prime.

It is a super-2 number, since 2×261005216131² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261005216131.

It is not an unprimeable number, because it can be changed into a prime (261005216111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2746755 + ... + 2840188.

It is an arithmetic number, because the mean of its divisors is an integer number (18503958528).

Almost surely, 2^261005216131 is an apocalyptic number.

261005216131 is a deficient number, since it is larger than the sum of its proper divisors (35058120317).

261005216131 is a wasteful number, since it uses less digits than its factorization.

261005216131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5587122.

The product of its (nonzero) digits is 2160, while the sum is 28.

Adding to 261005216131 its reverse (131612500162), we get a palindrome (392617716293).

The spelling of 261005216131 in words is "two hundred sixty-one billion, five million, two hundred sixteen thousand, one hundred thirty-one".