129120000 has 180 divisors, whose sum is σ = 431018280. Its totient is φ = 34304000.

The previous prime is 129119959. The next prime is 129120001. The reversal of 129120000 is 21921.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129120001) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 479866 + ... + 480134.

It is an arithmetic number, because the mean of its divisors is an integer number (2394546).

Almost surely, 2^129120000 is an apocalyptic number.

129120000 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 129120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215509140).

129120000 is an abundant number, since it is smaller than the sum of its proper divisors (301898280).

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

129120000 is an frugal number, since it uses more digits than its factorization.

129120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 129120000 is about 11363.0981690734. The cubic root of 129120000 is about 505.4340613381.

Adding to 129120000 its reverse (21921), we get a palindrome (129141921).

The spelling of 129120000 in words is "one hundred twenty-nine million, one hundred twenty thousand".