91661475 has 24 divisors (see below), whose sum is σ = 151990272. Its totient is φ = 48743200.

The previous prime is 91661461. The next prime is 91661483. The reversal of 91661475 is 57416619.

It is a Cunningham number, because it is equal to 9574²-1.

It is not a de Polignac number, because 91661475 - 2⁷ = 91661347 is a prime.

It is a super-3 number, since 3×91661475³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27130 + ... + 30320.

It is an arithmetic number, because the mean of its divisors is an integer number (6332928).

Almost surely, 2^91661475 is an apocalyptic number.

91661475 is a deficient number, since it is larger than the sum of its proper divisors (60328797).

91661475 is a wasteful number, since it uses less digits than its factorization.

91661475 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3587 (or 3582 counting only the distinct ones).

The product of its digits is 45360, while the sum is 39.

The square root of 91661475 is about 9573.9999477752. Note that the first 4 decimals coincide. The cubic root of 91661475 is about 450.8813590843.

The spelling of 91661475 in words is "ninety-one million, six hundred sixty-one thousand, four hundred seventy-five".