91664505 has 24 divisors (see below), whose sum is σ = 164366280. Its totient is φ = 47201280.

The previous prime is 91664497. The next prime is 91664543. The reversal of 91664505 is 50546619.

91664505 is a `hidden beast` number, since 9 + 1 + 6 + 645 + 0 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 39087504 + 52577001 = 6252^2 + 7251^2 .

It is not a de Polignac number, because 91664505 - 2³ = 91664497 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 91664505.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33816 + ... + 36425.

It is an arithmetic number, because the mean of its divisors is an integer number (6848595).

Almost surely, 2^91664505 is an apocalyptic number.

It is an amenable number.

91664505 is a deficient number, since it is larger than the sum of its proper divisors (72701775).

91664505 is a wasteful number, since it uses less digits than its factorization.

91664505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70281 (or 70278 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 91664505 is about 9574.1581875380. The cubic root of 91664505 is about 450.8863272037.

The spelling of 91664505 in words is "ninety-one million, six hundred sixty-four thousand, five hundred five".