129042720 has 144 divisors (see below), whose sum is σ = 456805440. Its totient is φ = 34401024.

The previous prime is 129042709. The next prime is 129042731. The reversal of 129042720 is 27240921.

It is an interprime number because it is at equal distance from previous prime (129042709) and next prime (129042731).

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

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

It is a zygodrome in base 3.

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, 37221 + ... + 40539.

It is an arithmetic number, because the mean of its divisors is an integer number (3172260).

Almost surely, 2^129042720 is an apocalyptic number.

129042720 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 129042720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (228402720).

129042720 is an abundant number, since it is smaller than the sum of its proper divisors (327762720).

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

129042720 is an equidigital number, since it uses as much as digits as its factorization.

129042720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3349 (or 3329 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 129042720 is about 11359.6971790625. The cubic root of 129042720 is about 505.3332049268. Note that the first 3 decimals are identical.

The spelling of 129042720 in words is "one hundred twenty-nine million, forty-two thousand, seven hundred twenty".