128400 has 60 divisors (see below), whose sum is σ = 415152. Its totient is φ = 33920.

The previous prime is 128399. The next prime is 128411. The reversal of 128400 is 4821.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 128400.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1147 + ... + 1253.

2¹²⁸⁴⁰⁰ is an apocalyptic number.

128400 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 128400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (207576).

128400 is an abundant number, since it is smaller than the sum of its proper divisors (286752).

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

128400 is a wasteful number, since it uses less digits than its factorization.

128400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 128400 is about 358.3294573434. The cubic root of 128400 is about 50.4492841169.

It can be divided in two parts, 128 and 400, that added together give a triangular number (528 = T₃₂).

The spelling of 128400 in words is "one hundred twenty-eight thousand, four hundred".