91221310587 has 8 divisors (see below), whose sum is σ = 132685542720. Its totient is φ = 55285642760.

The previous prime is 91221310577. The next prime is 91221310601. The reversal of 91221310587 is 78501312219.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 91221310587 - 2⁸ = 91221310331 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91221310577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1382141037 + ... + 1382141102.

It is an arithmetic number, because the mean of its divisors is an integer number (16585692840).

Almost surely, 2^91221310587 is an apocalyptic number.

91221310587 is a deficient number, since it is larger than the sum of its proper divisors (41464232133).

91221310587 is a wasteful number, since it uses less digits than its factorization.

91221310587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2764282153.

The product of its (nonzero) digits is 30240, while the sum is 39.

The spelling of 91221310587 in words is "ninety-one billion, two hundred twenty-one million, three hundred ten thousand, five hundred eighty-seven".