129105900 has 504 divisors, whose sum is σ = 546465024. Its totient is φ = 25660800.

The previous prime is 129105881. The next prime is 129105901. The reversal of 129105900 is 9501921.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (129105901) by changing a digit.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 5613289 + ... + 5613311.

It is an arithmetic number, because the mean of its divisors is an integer number (1084256).

Almost surely, 2^129105900 is an apocalyptic number.

129105900 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 129105900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (273232512).

129105900 is an abundant number, since it is smaller than the sum of its proper divisors (417359124).

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

129105900 is a wasteful number, since it uses less digits than its factorization.

129105900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 129105900 is about 11362.4777227504. The cubic root of 129105900 is about 505.4156627432.

The spelling of 129105900 in words is "one hundred twenty-nine million, one hundred five thousand, nine hundred".