128998440 has 128 divisors (see below), whose sum is σ = 443980800. Its totient is φ = 33281280.

The previous prime is 128998381. The next prime is 128998447. The reversal of 128998440 is 44899821.

It is a super-3 number, since 3×128998440³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (128998447) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31554 + ... + 35406.

It is an arithmetic number, because the mean of its divisors is an integer number (3468600).

Almost surely, 2^128998440 is an apocalyptic number.

128998440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128998440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221990400).

128998440 is an abundant number, since it is smaller than the sum of its proper divisors (314982360).

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

128998440 is a wasteful number, since it uses less digits than its factorization.

128998440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3904 (or 3894 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The square root of 128998440 is about 11357.7480162222. The cubic root of 128998440 is about 505.2753979354.

The spelling of 128998440 in words is "one hundred twenty-eight million, nine hundred ninety-eight thousand, four hundred forty".