128420 has 12 divisors (see below), whose sum is σ = 269724. Its totient is φ = 51360.

The previous prime is 128413. The next prime is 128431. The reversal of 128420 is 24821.

It can be written as a sum of positive squares in 2 ways, for example, as 40804 + 87616 = 202^2 + 296^2 .

It is an unprimeable number.

128420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3191 + ... + 3230.

It is an arithmetic number, because the mean of its divisors is an integer number (22477).

2¹²⁸⁴²⁰ is an apocalyptic number.

128420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128420 is an abundant number, since it is smaller than the sum of its proper divisors (141304).

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

128420 is a wasteful number, since it uses less digits than its factorization.

128420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6430 (or 6428 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 128420 is about 358.3573635353. The cubic root of 128420 is about 50.4519033622.

The spelling of 128420 in words is "one hundred twenty-eight thousand, four hundred twenty".