91123913 has 2 divisors, whose sum is σ = 91123914. Its totient is φ = 91123912.

The previous prime is 91123883. The next prime is 91123931. The reversal of 91123913 is 31932119.

Together with next prime (91123931) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78712384 + 12411529 = 8872^2 + 3523^2 .

It is a cyclic number.

It is not a de Polignac number, because 91123913 - 2⁸ = 91123657 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (91126913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45561956 + 45561957.

It is an arithmetic number, because the mean of its divisors is an integer number (45561957).

Almost surely, 2^91123913 is an apocalyptic number.

It is an amenable number.

91123913 is a deficient number, since it is larger than the sum of its proper divisors (1).

91123913 is an equidigital number, since it uses as much as digits as its factorization.

91123913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1458, while the sum is 29.

The square root of 91123913 is about 9545.8846106581. The cubic root of 91123913 is about 449.9982106925.

The spelling of 91123913 in words is "ninety-one million, one hundred twenty-three thousand, nine hundred thirteen".