131551939781161 has 2 divisors, whose sum is σ = 131551939781162. Its totient is φ = 131551939781160.

The previous prime is 131551939781107. The next prime is 131551939781203. The reversal of 131551939781161 is 161187939155131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125595504163600 + 5956435617561 = 11206940^2 + 2440581^2 .

It is a cyclic number.

It is not a de Polignac number, because 131551939781161 - 2²⁵ = 131551906226729 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131551939781161.

It is not a weakly prime, because it can be changed into another prime (131551939787161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65775969890580 + 65775969890581.

It is an arithmetic number, because the mean of its divisors is an integer number (65775969890581).

Almost surely, 2^{131551939781161} is an apocalyptic number.

It is an amenable number.

131551939781161 is a deficient number, since it is larger than the sum of its proper divisors (1).

131551939781161 is an equidigital number, since it uses as much as digits as its factorization.

131551939781161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6123600, while the sum is 61.

The spelling of 131551939781161 in words is "one hundred thirty-one trillion, five hundred fifty-one billion, nine hundred thirty-nine million, seven hundred eighty-one thousand, one hundred sixty-one".