91690 has 16 divisors (see below), whose sum is σ = 169128. Its totient is φ = 35776.

The previous prime is 91673. The next prime is 91691. The reversal of 91690 is 9619.

It can be written as a sum of positive squares in 4 ways, for example, as 90601 + 1089 = 301^2 + 33^2 .

It is a super-2 number, since 2×91690² = 16814112200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 444 + ... + 616.

2⁹¹⁶⁹⁰ is an apocalyptic number.

91690 is a deficient number, since it is larger than the sum of its proper divisors (77438).

91690 is a wasteful number, since it uses less digits than its factorization.

91690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233.

The product of its (nonzero) digits is 486, while the sum is 25.

The square root of 91690 is about 302.8035666897. The cubic root of 91690 is about 45.0928125576.

Subtracting from 91690 its product of nonzero digits (486), we obtain a square (91204 = 302²).

The spelling of 91690 in words is "ninety-one thousand, six hundred ninety".