128628 has 30 divisors (see below), whose sum is σ = 337106. Its totient is φ = 42768.

The previous prime is 128621. The next prime is 128629. The reversal of 128628 is 826821.

It can be written as a sum of positive squares in only one way, i.e., 116964 + 11664 = 342^2 + 108^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128621) by changing a digit.

128628 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 9 ways as a sum of consecutive naturals, for example, 126 + ... + 522.

2¹²⁸⁶²⁸ is an apocalyptic number.

128628 is a gapful number since it is divisible by the number (18) 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 128628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (168553).

128628 is an abundant number, since it is smaller than the sum of its proper divisors (208478).

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

128628 is a wasteful number, since it uses less digits than its factorization.

128628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413 (or 402 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 128628 is about 358.6474592131. The cubic root of 128628 is about 50.4791274066.

The spelling of 128628 in words is "one hundred twenty-eight thousand, six hundred twenty-eight".