91317139 has 2 divisors, whose sum is σ = 91317140. Its totient is φ = 91317138.

The previous prime is 91317133. The next prime is 91317151. The reversal of 91317139 is 93171319.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91317139 - 2³ = 91317131 is a prime.

It is not a weakly prime, because it can be changed into another prime (91317131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45658569 + 45658570.

It is an arithmetic number, because the mean of its divisors is an integer number (45658570).

Almost surely, 2^91317139 is an apocalyptic number.

91317139 is a deficient number, since it is larger than the sum of its proper divisors (1).

91317139 is an equidigital number, since it uses as much as digits as its factorization.

91317139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5103, while the sum is 34.

The square root of 91317139 is about 9556.0001569694. Note that the first 3 decimals coincide. The cubic root of 91317139 is about 450.3160561562.

The spelling of 91317139 in words is "ninety-one million, three hundred seventeen thousand, one hundred thirty-nine".