129133428 has 48 divisors (see below), whose sum is σ = 320967360. Its totient is φ = 40267264.

The previous prime is 129133427. The next prime is 129133447. The reversal of 129133428 is 824331921.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129133427) 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, 33463 + ... + 37121.

It is an arithmetic number, because the mean of its divisors is an integer number (6686820).

Almost surely, 2^129133428 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 129133428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160483680).

129133428 is an abundant number, since it is smaller than the sum of its proper divisors (191833932).

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

129133428 is a wasteful number, since it uses less digits than its factorization.

129133428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3856 (or 3854 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 129133428 is about 11363.6890136962. The cubic root of 129133428 is about 505.4515818185.

The spelling of 129133428 in words is "one hundred twenty-nine million, one hundred thirty-three thousand, four hundred twenty-eight".