128390940 has 96 divisors (see below), whose sum is σ = 405034560. Its totient is φ = 33758208.

The previous prime is 128390893. The next prime is 128390959. The reversal of 128390940 is 49093821.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 128390895 and 128390904.

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, 37792 + ... + 41048.

It is an arithmetic number, because the mean of its divisors is an integer number (4219110).

Almost surely, 2^128390940 is an apocalyptic number.

128390940 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 128390940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (202517280).

128390940 is an abundant number, since it is smaller than the sum of its proper divisors (276643620).

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

128390940 is a wasteful number, since it uses less digits than its factorization.

128390940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3348 (or 3340 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 128390940 is about 11330.9725972663. The cubic root of 128390940 is about 504.4809750923.

The spelling of 128390940 in words is "one hundred twenty-eight million, three hundred ninety thousand, nine hundred forty".