128109920 has 24 divisors (see below), whose sum is σ = 302660064. Its totient is φ = 51243904.

The previous prime is 128109911. The next prime is 128109929. The reversal of 128109920 is 29901821.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (128109911) and next prime (128109929).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128109929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 400184 + ... + 400503.

It is an arithmetic number, because the mean of its divisors is an integer number (12610836).

Almost surely, 2^128109920 is an apocalyptic number.

128109920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128109920 is an abundant number, since it is smaller than the sum of its proper divisors (174550144).

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

128109920 is an equidigital number, since it uses as much as digits as its factorization.

128109920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 800702 (or 800694 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 32.

The square root of 128109920 is about 11318.5652801051. The cubic root of 128109920 is about 504.1126396432.

The spelling of 128109920 in words is "one hundred twenty-eight million, one hundred nine thousand, nine hundred twenty".