129921120 has 144 divisors (see below), whose sum is σ = 506731680. Its totient is φ = 29693952.

The previous prime is 129921119. The next prime is 129921139. The reversal of 129921120 is 21129921.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3636 + ... + 16524.

It is an arithmetic number, because the mean of its divisors is an integer number (3518970).

Almost surely, 2^129921120 is an apocalyptic number.

129921120 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 129921120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253365840).

129921120 is an abundant number, since it is smaller than the sum of its proper divisors (376810560).

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

129921120 is a wasteful number, since it uses less digits than its factorization.

129921120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12917 (or 12906 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 129921120 is about 11398.2946092826. The cubic root of 129921120 is about 506.4772221881.

The spelling of 129921120 in words is "one hundred twenty-nine million, nine hundred twenty-one thousand, one hundred twenty".