91618571 has 4 divisors (see below), whose sum is σ = 99947544. Its totient is φ = 83289600.

The previous prime is 91618567. The next prime is 91618573. The reversal of 91618571 is 17581619.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91618571 - 2² = 91618567 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91618573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4164470 + ... + 4164491.

It is an arithmetic number, because the mean of its divisors is an integer number (24986886).

Almost surely, 2^91618571 is an apocalyptic number.

91618571 is a deficient number, since it is larger than the sum of its proper divisors (8328973).

91618571 is a wasteful number, since it uses less digits than its factorization.

91618571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8328972.

The product of its digits is 15120, while the sum is 38.

The square root of 91618571 is about 9571.7590337409. The cubic root of 91618571 is about 450.8110000709.

The spelling of 91618571 in words is "ninety-one million, six hundred eighteen thousand, five hundred seventy-one".