91985585 has 8 divisors (see below), whose sum is σ = 111521256. Its totient is φ = 72829440.

The previous prime is 91985549. The next prime is 91985609. The reversal of 91985585 is 58558919.

It can be written as a sum of positive squares in 4 ways, for example, as 23493409 + 68492176 = 4847^2 + 8276^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 91985585 - 2¹⁸ = 91723441 is a prime.

It is a super-2 number, since 2×91985585² = 16922695695584450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94346 + ... + 95315.

It is an arithmetic number, because the mean of its divisors is an integer number (13940157).

Almost surely, 2^91985585 is an apocalyptic number.

It is an amenable number.

91985585 is a deficient number, since it is larger than the sum of its proper divisors (19535671).

91985585 is a wasteful number, since it uses less digits than its factorization.

91985585 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189763.

The product of its digits is 648000, while the sum is 50.

The square root of 91985585 is about 9590.9115833689. The cubic root of 91985585 is about 451.4121646121.

The spelling of 91985585 in words is "ninety-one million, nine hundred eighty-five thousand, five hundred eighty-five".