129520 has 20 divisors (see below), whose sum is σ = 301320. Its totient is φ = 51776.

The previous prime is 129517. The next prime is 129527. The reversal of 129520 is 25921.

It is a tau number, because it is divible by the number of its divisors (20).

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129527) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 730 + ... + 889.

It is an arithmetic number, because the mean of its divisors is an integer number (15066).

2¹²⁹⁵²⁰ is an apocalyptic number.

129520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129520 is an abundant number, since it is smaller than the sum of its proper divisors (171800).

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

129520 is a wasteful number, since it uses less digits than its factorization.

129520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632 (or 1626 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 129520 is about 359.8888717368. Note that the first 4 decimals coincide. The cubic root of 129520 is about 50.5955450259.

The spelling of 129520 in words is "one hundred twenty-nine thousand, five hundred twenty".