128499999 has 8 divisors (see below), whose sum is σ = 171828480. Its totient is φ = 85419096.

The previous prime is 128499971. The next prime is 128500003. The reversal of 128499999 is 999994821.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-128499999 is a prime.

128499999 is a modest number, since divided by 99999 gives 1284 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128499949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60679 + ... + 62760.

It is an arithmetic number, because the mean of its divisors is an integer number (21478560).

Almost surely, 2^128499999 is an apocalyptic number.

128499999 is a deficient number, since it is larger than the sum of its proper divisors (43328481).

128499999 is a wasteful number, since it uses less digits than its factorization.

128499999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123789.

The product of its digits is 3779136, while the sum is 60.

The square root of 128499999 is about 11335.7840046465. The cubic root of 128499999 is about 504.6237749399.

The spelling of 128499999 in words is "one hundred twenty-eight million, four hundred ninety-nine thousand, nine hundred ninety-nine".