99321581091 has 32 divisors (see below), whose sum is σ = 134687784960. Its totient is φ = 65095856000.

The previous prime is 99321581089. The next prime is 99321581119. The reversal of 99321581091 is 19018512399.

It is a cyclic number.

It is not a de Polignac number, because 99321581091 - 2¹ = 99321581089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 99321581091.

It is not an unprimeable number, because it can be changed into a prime (99321581071) 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, 27733921 + ... + 27737501.

It is an arithmetic number, because the mean of its divisors is an integer number (4208993280).

Almost surely, 2^99321581091 is an apocalyptic number.

99321581091 is a deficient number, since it is larger than the sum of its proper divisors (35366203869).

99321581091 is a wasteful number, since it uses less digits than its factorization.

99321581091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4307.

The product of its (nonzero) digits is 174960, while the sum is 48.

The spelling of 99321581091 in words is "ninety-nine billion, three hundred twenty-one million, five hundred eighty-one thousand, ninety-one".