231231132201991 has 2 divisors, whose sum is σ = 231231132201992. Its totient is φ = 231231132201990.

The previous prime is 231231132201959. The next prime is 231231132202013. The reversal of 231231132201991 is 199102231132132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231231132201991 - 2⁵ = 231231132201959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231231132201191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115615566100995 + 115615566100996.

It is an arithmetic number, because the mean of its divisors is an integer number (115615566100996).

Almost surely, 2^{231231132201991} is an apocalyptic number.

231231132201991 is a deficient number, since it is larger than the sum of its proper divisors (1).

231231132201991 is an equidigital number, since it uses as much as digits as its factorization.

231231132201991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 40.

The spelling of 231231132201991 in words is "two hundred thirty-one trillion, two hundred thirty-one billion, one hundred thirty-two million, two hundred one thousand, nine hundred ninety-one".