99722991 has 4 divisors (see below), whose sum is σ = 132963992. Its totient is φ = 66481992.

The previous prime is 99722981. The next prime is 99722999. The reversal of 99722991 is 19922799.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 99722991 - 2⁶ = 99722927 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 99722991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99722999) 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, 16620496 + ... + 16620501.

It is an arithmetic number, because the mean of its divisors is an integer number (33240998).

Almost surely, 2^99722991 is an apocalyptic number.

99722991 is a deficient number, since it is larger than the sum of its proper divisors (33241001).

99722991 is a wasteful number, since it uses less digits than its factorization.

99722991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33241000.

The product of its digits is 183708, while the sum is 48.

The square root of 99722991 is about 9986.1399449437. The cubic root of 99722991 is about 463.7298997156.

The spelling of 99722991 in words is "ninety-nine million, seven hundred twenty-two thousand, nine hundred ninety-one".