128920 has 32 divisors (see below), whose sum is σ = 317520. Its totient is φ = 46720.

The previous prime is 128903. The next prime is 128923. The reversal of 128920 is 29821.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 128891 and 128900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128923) by changing a digit.

128920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 294 + ... + 586.

2¹²⁸⁹²⁰ is an apocalyptic number.

128920 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 128920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158760).

128920 is an abundant number, since it is smaller than the sum of its proper divisors (188600).

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

128920 is a wasteful number, since it uses less digits than its factorization.

128920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 128920 is about 359.0543134402. The cubic root of 128920 is about 50.5172963006.

Subtracting from 128920 its reverse (29821), we obtain a palindrome (99099).

The spelling of 128920 in words is "one hundred twenty-eight thousand, nine hundred twenty".