91690161 has 4 divisors (see below), whose sum is σ = 122253552. Its totient is φ = 61126772.

The previous prime is 91690153. The next prime is 91690187. The reversal of 91690161 is 16109619.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91690161 - 2³ = 91690153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91690861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15281691 + ... + 15281696.

It is an arithmetic number, because the mean of its divisors is an integer number (30563388).

Almost surely, 2^91690161 is an apocalyptic number.

It is an amenable number.

91690161 is a deficient number, since it is larger than the sum of its proper divisors (30563391).

91690161 is a wasteful number, since it uses less digits than its factorization.

91690161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30563390.

The product of its (nonzero) digits is 2916, while the sum is 33.

The square root of 91690161 is about 9575.4979504984. The cubic root of 91690161 is about 450.9283895066.

The spelling of 91690161 in words is "ninety-one million, six hundred ninety thousand, one hundred sixty-one".