128709840 has 160 divisors (see below), whose sum is σ = 475969536. Its totient is φ = 28131840.

The previous prime is 128709821. The next prime is 128709869. The reversal of 128709840 is 48907821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 36975 + ... + 40305.

Almost surely, 2^128709840 is an apocalyptic number.

128709840 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 128709840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (237984768).

128709840 is an abundant number, since it is smaller than the sum of its proper divisors (347259696).

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

128709840 is a wasteful number, since it uses less digits than its factorization.

128709840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3377 (or 3371 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 128709840 is about 11345.0359188501. The cubic root of 128709840 is about 504.8983097534.

The spelling of 128709840 in words is "one hundred twenty-eight million, seven hundred nine thousand, eight hundred forty".