261665116101311 has 32 divisors (see below), whose sum is σ = 292812879744000. Its totient is φ = 232262679801600.

The previous prime is 261665116101287. The next prime is 261665116101413. The reversal of 261665116101311 is 113101611566162.

It is a cyclic number.

It is not a de Polignac number, because 261665116101311 - 2⁶ = 261665116101247 is a prime.

It is a super-3 number, since 3×261665116101311³ (a number of 44 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261665116109311) 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 31 ways as a sum of consecutive naturals, for example, 136150940 + ... + 138059438.

It is an arithmetic number, because the mean of its divisors is an integer number (9150402492000).

Almost surely, 2^{261665116101311} is an apocalyptic number.

261665116101311 is a deficient number, since it is larger than the sum of its proper divisors (31147763642689).

261665116101311 is a wasteful number, since it uses less digits than its factorization.

261665116101311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912247.

The product of its (nonzero) digits is 38880, while the sum is 41.

Adding to 261665116101311 its reverse (113101611566162), we get a palindrome (374766727667473).

The spelling of 261665116101311 in words is "two hundred sixty-one trillion, six hundred sixty-five billion, one hundred sixteen million, one hundred one thousand, three hundred eleven".