99001891 has 4 divisors (see below), whose sum is σ = 99102784. Its totient is φ = 98901000.

The previous prime is 99001871. The next prime is 99001907. The reversal of 99001891 is 19810099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19810099 = 193 ⋅102643.

It is a cyclic number.

It is not a de Polignac number, because 99001891 - 2⁹ = 99001379 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 99001891.

It is not an unprimeable number, because it can be changed into a prime (99001801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48960 + ... + 50941.

It is an arithmetic number, because the mean of its divisors is an integer number (24775696).

Almost surely, 2^99001891 is an apocalyptic number.

99001891 is a deficient number, since it is larger than the sum of its proper divisors (100893).

99001891 is an equidigital number, since it uses as much as digits as its factorization.

99001891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100892.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 99001891 is about 9949.9693969379. The cubic root of 99001891 is about 462.6094463167.

The spelling of 99001891 in words is "ninety-nine million, one thousand, eight hundred ninety-one".