91100257 has 2 divisors, whose sum is σ = 91100258. Its totient is φ = 91100256.

The previous prime is 91100249. The next prime is 91100279. The reversal of 91100257 is 75200119.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91087936 + 12321 = 9544^2 + 111^2 .

It is a cyclic number.

It is not a de Polignac number, because 91100257 - 2³ = 91100249 is a prime.

It is not a weakly prime, because it can be changed into another prime (91100657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45550128 + 45550129.

It is an arithmetic number, because the mean of its divisors is an integer number (45550129).

Almost surely, 2^91100257 is an apocalyptic number.

It is an amenable number.

91100257 is a deficient number, since it is larger than the sum of its proper divisors (1).

91100257 is an equidigital number, since it uses as much as digits as its factorization.

91100257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 630, while the sum is 25.

The square root of 91100257 is about 9544.6454622474. The cubic root of 91100257 is about 449.9592670950.

The spelling of 91100257 in words is "ninety-one million, one hundred thousand, two hundred fifty-seven".