91861711231 has 2 divisors, whose sum is σ = 91861711232. Its totient is φ = 91861711230.

The previous prime is 91861711169. The next prime is 91861711283. The reversal of 91861711231 is 13211716819.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91861711231 - 2⁷ = 91861711103 is a prime.

It is a super-2 number, since 2×91861711231² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91861211231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45930855615 + 45930855616.

It is an arithmetic number, because the mean of its divisors is an integer number (45930855616).

Almost surely, 2^91861711231 is an apocalyptic number.

91861711231 is a deficient number, since it is larger than the sum of its proper divisors (1).

91861711231 is an equidigital number, since it uses as much as digits as its factorization.

91861711231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 40.

The spelling of 91861711231 in words is "ninety-one billion, eight hundred sixty-one million, seven hundred eleven thousand, two hundred thirty-one".