91137217 has 2 divisors, whose sum is σ = 91137218. Its totient is φ = 91137216.

The previous prime is 91137173. The next prime is 91137257. The reversal of 91137217 is 71273119.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68707521 + 22429696 = 8289^2 + 4736^2 .

It is a cyclic number.

It is not a de Polignac number, because 91137217 - 2²³ = 82748609 is a prime.

It is not a weakly prime, because it can be changed into another prime (91137257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45568608 + 45568609.

It is an arithmetic number, because the mean of its divisors is an integer number (45568609).

Almost surely, 2^91137217 is an apocalyptic number.

It is an amenable number.

91137217 is a deficient number, since it is larger than the sum of its proper divisors (1).

91137217 is an equidigital number, since it uses as much as digits as its factorization.

91137217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2646, while the sum is 31.

The square root of 91137217 is about 9546.5814300199. The cubic root of 91137217 is about 450.0201093894.

The spelling of 91137217 in words is "ninety-one million, one hundred thirty-seven thousand, two hundred seventeen".