13031011991 has 2 divisors, whose sum is σ = 13031011992. Its totient is φ = 13031011990.

The previous prime is 13031011963. The next prime is 13031012053. The reversal of 13031011991 is 19911013031.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13031011991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13031011291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6515505995 + 6515505996.

It is an arithmetic number, because the mean of its divisors is an integer number (6515505996).

Almost surely, 2^13031011991 is an apocalyptic number.

13031011991 is a deficient number, since it is larger than the sum of its proper divisors (1).

13031011991 is an equidigital number, since it uses as much as digits as its factorization.

13031011991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 29.

The spelling of 13031011991 in words is "thirteen billion, thirty-one million, eleven thousand, nine hundred ninety-one".