128899998 has 20 divisors (see below), whose sum is σ = 288831840. Its totient is φ = 42966612.

The previous prime is 128899997. The next prime is 128899999. The reversal of 128899998 is 899998821.

It is an interprime number because it is at equal distance from previous prime (128899997) and next prime (128899999).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128899993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 397678 + ... + 398001.

It is an arithmetic number, because the mean of its divisors is an integer number (14441592).

Almost surely, 2^128899998 is an apocalyptic number.

128899998 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

128899998 is an abundant number, since it is smaller than the sum of its proper divisors (159931842).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128899998 is an equidigital number, since it uses as much as digits as its factorization.

128899998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795693 (or 795684 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 63.

The square root of 128899998 is about 11353.4134955087. The cubic root of 128899998 is about 505.1468357120.

The spelling of 128899998 in words is "one hundred twenty-eight million, eight hundred ninety-nine thousand, nine hundred ninety-eight".