99993989 has 4 divisors (see below), whose sum is σ = 100225356. Its totient is φ = 99762624.

The previous prime is 99993947. The next prime is 99993991. The reversal of 99993989 is 98939999.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8025889 + 91968100 = 2833^2 + 9590^2 .

It is a cyclic number.

It is not a de Polignac number, because 99993989 - 2²⁴ = 83216773 is a prime.

It is a super-2 number, since 2×99993989² = 19997595672264242, 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 (99993889) 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, 115034 + ... + 115899.

It is an arithmetic number, because the mean of its divisors is an integer number (25056339).

Almost surely, 2^99993989 is an apocalyptic number.

It is an amenable number.

99993989 is a deficient number, since it is larger than the sum of its proper divisors (231367).

99993989 is a wasteful number, since it uses less digits than its factorization.

99993989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231366.

The product of its digits is 12754584, while the sum is 65.

The square root of 99993989 is about 9999.6994454833. The cubic root of 99993989 is about 464.1495829781.

The spelling of 99993989 in words is "ninety-nine million, nine hundred ninety-three thousand, nine hundred eighty-nine".