129105920 has 72 divisors (see below), whose sum is σ = 311425884. Its totient is φ = 51380224.

The previous prime is 129105901. The next prime is 129105937. The reversal of 129105920 is 29501921.

It can be written as a sum of positive squares in 2 ways, for example, as 121176064 + 7929856 = 11008^2 + 2816^2 .

It is a nialpdrome in base 8.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 655262 + ... + 655458.

Almost surely, 2^129105920 is an apocalyptic number.

129105920 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 129105920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155712942).

129105920 is an abundant number, since it is smaller than the sum of its proper divisors (182319964).

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

129105920 is an frugal number, since it uses more digits than its factorization.

129105920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 129105920 is about 11362.4786028401. The cubic root of 129105920 is about 505.4156888415.

The spelling of 129105920 in words is "one hundred twenty-nine million, one hundred five thousand, nine hundred twenty".