91157305 has 4 divisors (see below), whose sum is σ = 109388772. Its totient is φ = 72925840.

The previous prime is 91157263. The next prime is 91157317. The reversal of 91157305 is 50375119.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50375119 = 1021 ⋅49339.

It can be written as a sum of positive squares in 2 ways, for example, as 17952169 + 73205136 = 4237^2 + 8556^2 .

It is not a de Polignac number, because 91157305 - 2²⁵ = 57602873 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9115726 + ... + 9115735.

It is an arithmetic number, because the mean of its divisors is an integer number (27347193).

Almost surely, 2^91157305 is an apocalyptic number.

It is an amenable number.

91157305 is a deficient number, since it is larger than the sum of its proper divisors (18231467).

91157305 is a wasteful number, since it uses less digits than its factorization.

91157305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18231466.

The product of its (nonzero) digits is 4725, while the sum is 31.

The square root of 91157305 is about 9547.6334764171. The cubic root of 91157305 is about 450.0531706720.

The spelling of 91157305 in words is "ninety-one million, one hundred fifty-seven thousand, three hundred five".