91821536895 has 32 divisors (see below), whose sum is σ = 160369657344. Its totient is φ = 44491939200.

The previous prime is 91821536867. The next prime is 91821536899. The reversal of 91821536895 is 59863512819.

It is a happy number.

It is not a de Polignac number, because 91821536895 - 2²¹ = 91819439743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91821536899) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 95814 + ... + 439116.

It is an arithmetic number, because the mean of its divisors is an integer number (5011551792).

Almost surely, 2^91821536895 is an apocalyptic number.

91821536895 is a deficient number, since it is larger than the sum of its proper divisors (68548120449).

91821536895 is a wasteful number, since it uses less digits than its factorization.

91821536895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344943.

The product of its digits is 4665600, while the sum is 57.

The spelling of 91821536895 in words is "ninety-one billion, eight hundred twenty-one million, five hundred thirty-six thousand, eight hundred ninety-five".