99388691 has 4 divisors (see below), whose sum is σ = 101503392. Its totient is φ = 97273992.

The previous prime is 99388687. The next prime is 99388741. The reversal of 99388691 is 19688399.

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

It is a cyclic number.

It is not a de Polignac number, because 99388691 - 2² = 99388687 is a prime.

It is a super-2 number, since 2×99388691² = 19756223797386962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99388651) 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, 1057280 + ... + 1057373.

It is an arithmetic number, because the mean of its divisors is an integer number (25375848).

Almost surely, 2^99388691 is an apocalyptic number.

99388691 is a deficient number, since it is larger than the sum of its proper divisors (2114701).

99388691 is a wasteful number, since it uses less digits than its factorization.

99388691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2114700.

The product of its digits is 839808, while the sum is 53.

The square root of 99388691 is about 9969.3876943371. The cubic root of 99388691 is about 463.2111344956.

The spelling of 99388691 in words is "ninety-nine million, three hundred eighty-eight thousand, six hundred ninety-one".