129800 has 48 divisors (see below), whose sum is σ = 334800. Its totient is φ = 46400.

The previous prime is 129793. The next prime is 129803. The reversal of 129800 is 8921.

129800 = T₂₀₅ + T₂₀₆ + ... + T₂₁₀.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (129803) by changing a digit.

129800 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2171 + ... + 2229.

It is an arithmetic number, because the mean of its divisors is an integer number (6975).

2¹²⁹⁸⁰⁰ is an apocalyptic number.

129800 is a gapful number since it is divisible by the number (10) 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 129800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167400).

129800 is an abundant number, since it is smaller than the sum of its proper divisors (205000).

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

129800 is a wasteful number, since it uses less digits than its factorization.

129800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 129800 is about 360.2776706930. The cubic root of 129800 is about 50.6319784111.

It can be divided in two parts, 129 and 800, that added together give a palindrome (929).

The spelling of 129800 in words is "one hundred twenty-nine thousand, eight hundred".