129728 has 14 divisors (see below), whose sum is σ = 257556. Its totient is φ = 64832.

The previous prime is 129719. The next prime is 129733. The reversal of 129728 is 827921.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 129728.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 950 + ... + 1077.

2¹²⁹⁷²⁸ is an apocalyptic number.

It is an amenable number.

129728 is a deficient number, since it is larger than the sum of its proper divisors (127828).

129728 is an equidigital number, since it uses as much as digits as its factorization.

129728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2039 (or 2029 counting only the distinct ones).

The product of its digits is 2016, while the sum is 29.

The square root of 129728 is about 360.1777339037. The cubic root of 129728 is about 50.6226148345.

The spelling of 129728 in words is "one hundred twenty-nine thousand, seven hundred twenty-eight".