99888889 has 4 divisors (see below), whose sum is σ = 105764724. Its totient is φ = 94013056.

The previous prime is 99888881. The next prime is 99888911. The reversal of 99888889 is 98888899.

It is a happy number.

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 37210000 + 62678889 = 6100^2 + 7917^2 .

It is a cyclic number.

It is not a de Polignac number, because 99888889 - 2³ = 99888881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99888881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2937892 + ... + 2937925.

It is an arithmetic number, because the mean of its divisors is an integer number (26441181).

Almost surely, 2^99888889 is an apocalyptic number.

It is an amenable number.

99888889 is a deficient number, since it is larger than the sum of its proper divisors (5875835).

99888889 is a wasteful number, since it uses less digits than its factorization.

99888889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5875834.

The product of its digits is 23887872, while the sum is 67.

The square root of 99888889 is about 9994.4429059353. The cubic root of 99888889 is about 463.9869091258.

It can be divided in two parts, 99 and 888889, that multiplied together give a triangular number (88000011 = T₁₃₂₆₆).

The spelling of 99888889 in words is "ninety-nine million, eight hundred eighty-eight thousand, eight hundred eighty-nine".