129428224 has 72 divisors (see below), whose sum is σ = 273143808. Its totient is φ = 61117440.

The previous prime is 129428219. The next prime is 129428231. The reversal of 129428224 is 422824921.

It is a self number, because there is not a number n which added to its sum of digits gives 129428224.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 372819 + ... + 373165.

It is an arithmetic number, because the mean of its divisors is an integer number (3793664).

Almost surely, 2^129428224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129428224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (136571904).

129428224 is an abundant number, since it is smaller than the sum of its proper divisors (143715584).

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

129428224 is an equidigital number, since it uses as much as digits as its factorization.

129428224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 427 counting only the distinct ones).

The product of its digits is 18432, while the sum is 34.

The square root of 129428224 is about 11376.6525832514. The cubic root of 129428224 is about 505.8359177815.

The spelling of 129428224 in words is "one hundred twenty-nine million, four hundred twenty-eight thousand, two hundred twenty-four".