129431328 has 96 divisors (see below), whose sum is σ = 375915456. Its totient is φ = 38734848.

The previous prime is 129431317. The next prime is 129431329. The reversal of 129431328 is 823134921.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (129431329) 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, 44775 + ... + 47577.

It is an arithmetic number, because the mean of its divisors is an integer number (3915786).

Almost surely, 2^129431328 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 129431328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (187957728).

129431328 is an abundant number, since it is smaller than the sum of its proper divisors (246484128).

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

129431328 is a wasteful number, since it uses less digits than its factorization.

129431328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2866 (or 2858 counting only the distinct ones).

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

The square root of 129431328 is about 11376.7890021746. The cubic root of 129431328 is about 505.8399614697.

The spelling of 129431328 in words is "one hundred twenty-nine million, four hundred thirty-one thousand, three hundred twenty-eight".