91609666 has 16 divisors (see below), whose sum is σ = 142394040. Its totient is φ = 44150400.

The previous prime is 91609663. The next prime is 91609691. The reversal of 91609666 is 66690619.

It can be written as a sum of positive squares in 4 ways, for example, as 77704225 + 13905441 = 8815^2 + 3729^2 .

It is not an unprimeable number, because it can be changed into a prime (91609663) 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, 49966 + ... + 51766.

Almost surely, 2^91609666 is an apocalyptic number.

91609666 is a deficient number, since it is larger than the sum of its proper divisors (50784374).

91609666 is a wasteful number, since it uses less digits than its factorization.

91609666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709.

The product of its (nonzero) digits is 104976, while the sum is 43.

The square root of 91609666 is about 9571.2938519304. The cubic root of 91609666 is about 450.7963938545.

The spelling of 91609666 in words is "ninety-one million, six hundred nine thousand, six hundred sixty-six".