91365561 has 24 divisors (see below), whose sum is σ = 152390784. Its totient is φ = 51667200.

The previous prime is 91365541. The next prime is 91365577. The reversal of 91365561 is 16556319.

91365561 is a `hidden beast` number, since 91 + 3 + 6 + 5 + 561 = 666.

It is not a de Polignac number, because 91365561 - 2⁵ = 91365529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91365511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1365 + ... + 13586.

It is an arithmetic number, because the mean of its divisors is an integer number (6349616).

Almost surely, 2^91365561 is an apocalyptic number.

It is an amenable number.

91365561 is a deficient number, since it is larger than the sum of its proper divisors (61025223).

91365561 is a wasteful number, since it uses less digits than its factorization.

91365561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15061 (or 15058 counting only the distinct ones).

The product of its digits is 24300, while the sum is 36.

The square root of 91365561 is about 9558.5334126110. The cubic root of 91365561 is about 450.3956372414.

The spelling of 91365561 in words is "ninety-one million, three hundred sixty-five thousand, five hundred sixty-one".