129105728 has 28 divisors (see below), whose sum is σ = 263123172. Its totient is φ = 62807040.

The previous prime is 129105727. The next prime is 129105751. The reversal of 129105728 is 827501921.

It can be written as a sum of positive squares in 2 ways, for example, as 87011584 + 42094144 = 9328^2 + 6488^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129105727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24893 + ... + 29628.

Almost surely, 2^129105728 is an apocalyptic number.

It is an amenable number.

129105728 is an abundant number, since it is smaller than the sum of its proper divisors (134017444).

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

129105728 is an equidigital number, since it uses as much as digits as its factorization.

129105728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54570 (or 54560 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 129105728 is about 11362.4701539762. The cubic root of 129105728 is about 505.4154382982.

The spelling of 129105728 in words is "one hundred twenty-nine million, one hundred five thousand, seven hundred twenty-eight".