999999889 has 12 divisors (see below), whose sum is σ = 1174788468. Its totient is φ = 848652000.

The previous prime is 999999883. The next prime is 999999893. The reversal of 999999889 is 988999999.

It can be written as a sum of positive squares in 2 ways, for example, as 851647489 + 148352400 = 29183^2 + 12180^2 .

It is not a de Polignac number, because 999999889 - 2⁷ = 999999761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (999999883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 96082 + ... + 105979.

It is an arithmetic number, because the mean of its divisors is an integer number (97899039).

Almost surely, 2^999999889 is an apocalyptic number.

It is an amenable number.

999999889 is a deficient number, since it is larger than the sum of its proper divisors (174788579).

999999889 is a wasteful number, since it uses less digits than its factorization.

999999889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202176 (or 202169 counting only the distinct ones).

The product of its digits is 306110016, while the sum is 79.

The square root of 999999889 is about 31622.7748466196. The cubic root of 999999889 is about 999.9999630000. Note that the first 4 decimals are identical.

The spelling of 999999889 in words is "nine hundred ninety-nine million, nine hundred ninety-nine thousand, eight hundred eighty-nine".