91197913 has 2 divisors, whose sum is σ = 91197914. Its totient is φ = 91197912.

The previous prime is 91197901. The next prime is 91197937. The reversal of 91197913 is 31979119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71368704 + 19829209 = 8448^2 + 4453^2 .

It is an emirp because it is prime and its reverse (31979119) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91197913 is a prime.

It is not a weakly prime, because it can be changed into another prime (91197973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45598956 + 45598957.

It is an arithmetic number, because the mean of its divisors is an integer number (45598957).

Almost surely, 2^91197913 is an apocalyptic number.

It is an amenable number.

91197913 is a deficient number, since it is larger than the sum of its proper divisors (1).

91197913 is an equidigital number, since it uses as much as digits as its factorization.

91197913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15309, while the sum is 40.

The square root of 91197913 is about 9549.7598399122. The cubic root of 91197913 is about 450.1199894020.

The spelling of 91197913 in words is "ninety-one million, one hundred ninety-seven thousand, nine hundred thirteen".