128599999 has 16 divisors (see below), whose sum is σ = 150192000. Its totient is φ = 108868320.

The previous prime is 128599987. The next prime is 128600027. The reversal of 128599999 is 999995821.

It is not a de Polignac number, because 128599999 - 2²³ = 120211391 is a prime.

It is a Duffinian number.

128599999 is a modest number, since divided by 99999 gives 1285 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128599979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7117 + ... + 17545.

It is an arithmetic number, because the mean of its divisors is an integer number (9387000).

Almost surely, 2^128599999 is an apocalyptic number.

128599999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

128599999 is a deficient number, since it is larger than the sum of its proper divisors (21592001).

128599999 is a wasteful number, since it uses less digits than its factorization.

128599999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10518.

The product of its digits is 4723920, while the sum is 61.

The square root of 128599999 is about 11340.1939577769. The cubic root of 128599999 is about 504.7546421083.

The spelling of 128599999 in words is "one hundred twenty-eight million, five hundred ninety-nine thousand, nine hundred ninety-nine".