91557149 has 2 divisors, whose sum is σ = 91557150. Its totient is φ = 91557148.

The previous prime is 91557133. The next prime is 91557161. The reversal of 91557149 is 94175519.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91336249 + 220900 = 9557^2 + 470^2 .

It is a cyclic number.

It is not a de Polignac number, because 91557149 - 2⁴ = 91557133 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91557119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45778574 + 45778575.

It is an arithmetic number, because the mean of its divisors is an integer number (45778575).

Almost surely, 2^91557149 is an apocalyptic number.

It is an amenable number.

91557149 is a deficient number, since it is larger than the sum of its proper divisors (1).

91557149 is an equidigital number, since it uses as much as digits as its factorization.

91557149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56700, while the sum is 41.

The square root of 91557149 is about 9568.5499946439. The cubic root of 91557149 is about 450.7102348255.

The spelling of 91557149 in words is "ninety-one million, five hundred fifty-seven thousand, one hundred forty-nine".