91215587 has 8 divisors (see below), whose sum is σ = 92062176. Its totient is φ = 90372672.

The previous prime is 91215569. The next prime is 91215613. The reversal of 91215587 is 78551219.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91215587 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91215587.

It is not an unprimeable number, because it can be changed into a prime (91215287) 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, 75863 + ... + 77055.

It is an arithmetic number, because the mean of its divisors is an integer number (11507772).

Almost surely, 2^91215587 is an apocalyptic number.

91215587 is a deficient number, since it is larger than the sum of its proper divisors (846589).

91215587 is a wasteful number, since it uses less digits than its factorization.

91215587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1837.

The product of its digits is 25200, while the sum is 38.

The square root of 91215587 is about 9550.6851586679. The cubic root of 91215587 is about 450.1490650192.

The spelling of 91215587 in words is "ninety-one million, two hundred fifteen thousand, five hundred eighty-seven".