129780 has 72 divisors (see below), whose sum is σ = 454272. Its totient is φ = 29376.

The previous prime is 129769. The next prime is 129793. The reversal of 129780 is 87921.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1209 + ... + 1311.

2¹²⁹⁷⁸⁰ is an apocalyptic number.

129780 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 129780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (227136).

129780 is an abundant number, since it is smaller than the sum of its proper divisors (324492).

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

129780 is a wasteful number, since it uses less digits than its factorization.

129780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 129780 is about 360.2499132547. The cubic root of 129780 is about 50.6293777650.

It can be divided in two parts, 129 and 780, that added together give a palindrome (909).

The spelling of 129780 in words is "one hundred twenty-nine thousand, seven hundred eighty".