135728 has 20 divisors (see below), whose sum is σ = 279000. Its totient is φ = 63744.

The previous prime is 135727. The next prime is 135731. The reversal of 135728 is 827531.

It is a plaindrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 135697 and 135706.

It is not an unprimeable number, because it can be changed into a prime (135721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23 + ... + 521.

It is an arithmetic number, because the mean of its divisors is an integer number (13950).

2¹³⁵⁷²⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 135728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139500).

135728 is an abundant number, since it is smaller than the sum of its proper divisors (143272).

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

135728 is a wasteful number, since it uses less digits than its factorization.

135728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524 (or 518 counting only the distinct ones).

The product of its digits is 1680, while the sum is 26.

The square root of 135728 is about 368.4128119379. The cubic root of 135728 is about 51.3913251774.

The spelling of 135728 in words is "one hundred thirty-five thousand, seven hundred twenty-eight".