129361920 has 96 divisors (see below), whose sum is σ = 413955360. Its totient is φ = 34488320.

The previous prime is 129361919. The next prime is 129361927. The reversal of 129361920 is 29163921.

It is a tau number, because it is divible by the number of its divisors (96).

It is not an unprimeable number, because it can be changed into a prime (129361927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28615 + ... + 32825.

It is an arithmetic number, because the mean of its divisors is an integer number (4312035).

Almost surely, 2^129361920 is an apocalyptic number.

129361920 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 129361920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (206977680).

129361920 is an abundant number, since it is smaller than the sum of its proper divisors (284593440).

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

129361920 is an equidigital number, since it uses as much as digits as its factorization.

129361920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4241 (or 4221 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 33.

The square root of 129361920 is about 11373.7381717710. The cubic root of 129361920 is about 505.7495258225.

The spelling of 129361920 in words is "one hundred twenty-nine million, three hundred sixty-one thousand, nine hundred twenty".