99189791 has 4 divisors (see below), whose sum is σ = 99222000. Its totient is φ = 99157584.

The previous prime is 99189767. The next prime is 99189799. The reversal of 99189791 is 19798199.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19798199 = 1423 ⋅13913.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99189791 is a prime.

It is a super-2 number, since 2×99189791² = 19677229277247362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99189799) 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, 10931 + ... + 17828.

It is an arithmetic number, because the mean of its divisors is an integer number (24805500).

Almost surely, 2^99189791 is an apocalyptic number.

99189791 is a deficient number, since it is larger than the sum of its proper divisors (32209).

99189791 is a wasteful number, since it uses less digits than its factorization.

99189791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32208.

The product of its digits is 367416, while the sum is 53.

The square root of 99189791 is about 9959.4071610714. The cubic root of 99189791 is about 462.9019302262.

The spelling of 99189791 in words is "ninety-nine million, one hundred eighty-nine thousand, seven hundred ninety-one".