123591991231 has 2 divisors, whose sum is σ = 123591991232. Its totient is φ = 123591991230.

The previous prime is 123591991223. The next prime is 123591991247. The reversal of 123591991231 is 132199195321.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 123591991231 - 2³ = 123591991223 is a prime.

It is a super-2 number, since 2×123591991231² (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 (123591901231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61795995615 + 61795995616.

It is an arithmetic number, because the mean of its divisors is an integer number (61795995616).

Almost surely, 2^123591991231 is an apocalyptic number.

123591991231 is a deficient number, since it is larger than the sum of its proper divisors (1).

123591991231 is an equidigital number, since it uses as much as digits as its factorization.

123591991231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131220, while the sum is 46.

The spelling of 123591991231 in words is "one hundred twenty-three billion, five hundred ninety-one million, nine hundred ninety-one thousand, two hundred thirty-one".