91039491913 has 2 divisors, whose sum is σ = 91039491914. Its totient is φ = 91039491912.

The previous prime is 91039491901. The next prime is 91039491919. The reversal of 91039491913 is 31919493019.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90737705529 + 301786384 = 301227^2 + 17372^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91039491913 is a prime.

It is not a weakly prime, because it can be changed into another prime (91039491919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45519745956 + 45519745957.

It is an arithmetic number, because the mean of its divisors is an integer number (45519745957).

Almost surely, 2^91039491913 is an apocalyptic number.

It is an amenable number.

91039491913 is a deficient number, since it is larger than the sum of its proper divisors (1).

91039491913 is an equidigital number, since it uses as much as digits as its factorization.

91039491913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 236196, while the sum is 49.

The spelling of 91039491913 in words is "ninety-one billion, thirty-nine million, four hundred ninety-one thousand, nine hundred thirteen".