129023280 has 120 divisors (see below), whose sum is σ = 449419152. Its totient is φ = 34401024.

The previous prime is 129023231. The next prime is 129023299. The reversal of 129023280 is 82320921.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 16122 + ... + 22758.

Almost surely, 2^129023280 is an apocalyptic number.

129023280 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 129023280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224709576).

129023280 is an abundant number, since it is smaller than the sum of its proper divisors (320395872).

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

129023280 is an equidigital number, since it uses as much as digits as its factorization.

129023280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6665 (or 6647 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 129023280 is about 11358.8414902225. The cubic root of 129023280 is about 505.3078278763.

The spelling of 129023280 in words is "one hundred twenty-nine million, twenty-three thousand, two hundred eighty".