129220 has 48 divisors (see below), whose sum is σ = 338688. Its totient is φ = 40320.

The previous prime is 129209. The next prime is 129221. The reversal of 129220 is 22921.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 129194 and 129203.

It is not an unprimeable number, because it can be changed into a prime (129221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1785 + ... + 1855.

It is an arithmetic number, because the mean of its divisors is an integer number (7056).

2¹²⁹²²⁰ is an apocalyptic number.

129220 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 129220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169344).

129220 is an abundant number, since it is smaller than the sum of its proper divisors (209468).

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

129220 is a wasteful number, since it uses less digits than its factorization.

129220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 129220 is about 359.4718347799. The cubic root of 129220 is about 50.5564509406.

The spelling of 129220 in words is "one hundred twenty-nine thousand, two hundred twenty".