128724 has 24 divisors (see below), whose sum is σ = 318528. Its totient is φ = 40320.

The previous prime is 128717. The next prime is 128747. The reversal of 128724 is 427821.

It is a plaindrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 128694 and 128703.

It is a congruent number.

It is an unprimeable number.

128724 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, 112 + ... + 519.

It is an arithmetic number, because the mean of its divisors is an integer number (13272).

2¹²⁸⁷²⁴ is an apocalyptic number.

It is an amenable number.

128724 is an abundant number, since it is smaller than the sum of its proper divisors (189804).

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

128724 is a wasteful number, since it uses less digits than its factorization.

128724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655 (or 653 counting only the distinct ones).

The product of its digits is 896, while the sum is 24.

The square root of 128724 is about 358.7812704142. The cubic root of 128724 is about 50.4916824520.

The spelling of 128724 in words is "one hundred twenty-eight thousand, seven hundred twenty-four".