91311917 has 2 divisors, whose sum is σ = 91311918. Its totient is φ = 91311916.

The previous prime is 91311911. The next prime is 91311949. The reversal of 91311917 is 71911319.

It is an a-pointer prime, because the next prime (91311949) can be obtained adding 91311917 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56040196 + 35271721 = 7486^2 + 5939^2 .

It is an emirp because it is prime and its reverse (71911319) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91311917 - 2⁴ = 91311901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91311911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45655958 + 45655959.

It is an arithmetic number, because the mean of its divisors is an integer number (45655959).

Almost surely, 2^91311917 is an apocalyptic number.

It is an amenable number.

91311917 is a deficient number, since it is larger than the sum of its proper divisors (1).

91311917 is an equidigital number, since it uses as much as digits as its factorization.

91311917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1701, while the sum is 32.

The square root of 91311917 is about 9555.7269215900. The cubic root of 91311917 is about 450.3074721697.

The spelling of 91311917 in words is "ninety-one million, three hundred eleven thousand, nine hundred seventeen".