91661685 has 16 divisors (see below), whose sum is σ = 147206400. Its totient is φ = 48703680.

The previous prime is 91661659. The next prime is 91661707. The reversal of 91661685 is 58616619.

It is a happy number.

It is not a de Polignac number, because 91661685 - 2¹² = 91657589 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7210 + ... + 15339.

It is an arithmetic number, because the mean of its divisors is an integer number (9200400).

Almost surely, 2^91661685 is an apocalyptic number.

It is an amenable number.

91661685 is a deficient number, since it is larger than the sum of its proper divisors (55544715).

91661685 is a wasteful number, since it uses less digits than its factorization.

91661685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22828.

The product of its digits is 77760, while the sum is 42.

The square root of 91661685 is about 9574.0109149718. The cubic root of 91661685 is about 450.8817034129.

The spelling of 91661685 in words is "ninety-one million, six hundred sixty-one thousand, six hundred eighty-five".