129012120 has 96 divisors (see below), whose sum is σ = 421312320. Its totient is φ = 34237440.

The previous prime is 129012119. The next prime is 129012127. The reversal of 129012120 is 21210921.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 129012093 and 129012102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129012127) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86017 + ... + 87503.

It is an arithmetic number, because the mean of its divisors is an integer number (4388670).

Almost surely, 2^129012120 is an apocalyptic number.

129012120 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 129012120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (210656160).

129012120 is an abundant number, since it is smaller than the sum of its proper divisors (292300200).

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

129012120 is a wasteful number, since it uses less digits than its factorization.

129012120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 129012120 is about 11358.3502323181. The cubic root of 129012120 is about 505.2932584178.

The spelling of 129012120 in words is "one hundred twenty-nine million, twelve thousand, one hundred twenty".