129142728 has 256 divisors, whose sum is σ = 436665600. Its totient is φ = 34836480.

The previous prime is 129142709. The next prime is 129142729. The reversal of 129142728 is 827241921.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 129142692 and 129142701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129142729) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1142800 + ... + 1142912.

It is an arithmetic number, because the mean of its divisors is an integer number (1705725).

Almost surely, 2^129142728 is an apocalyptic number.

129142728 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 129142728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (218332800).

129142728 is an abundant number, since it is smaller than the sum of its proper divisors (307522872).

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

129142728 is a wasteful number, since it uses less digits than its factorization.

129142728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 179 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 129142728 is about 11364.0982044331. The cubic root of 129142728 is about 505.4637154877.

The spelling of 129142728 in words is "one hundred twenty-nine million, one hundred forty-two thousand, seven hundred twenty-eight".