129835520 has 80 divisors (see below), whose sum is σ = 319151448. Its totient is φ = 50626560.

The previous prime is 129835513. The next prime is 129835547. The reversal of 129835520 is 25538921.

It can be written as a sum of positive squares in 4 ways, for example, as 87011584 + 42823936 = 9328^2 + 6544^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 104342 + ... + 105578.

Almost surely, 2^129835520 is an apocalyptic number.

129835520 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 129835520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159575724).

129835520 is an abundant number, since it is smaller than the sum of its proper divisors (189315928).

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

129835520 is an equidigital number, since it uses as much as digits as its factorization.

129835520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1301 (or 1285 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 129835520 is about 11394.5390428924. The cubic root of 129835520 is about 506.3659650006.

The spelling of 129835520 in words is "one hundred twenty-nine million, eight hundred thirty-five thousand, five hundred twenty".