129141520 has 80 divisors (see below), whose sum is σ = 320001840. Its totient is φ = 48300032.

The previous prime is 129141497. The next prime is 129141521. The reversal of 129141520 is 25141921.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 6906384 + 122235136 = 2628^2 + 11056^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (129141521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 365664 + ... + 366016.

It is an arithmetic number, because the mean of its divisors is an integer number (4000023).

Almost surely, 2^129141520 is an apocalyptic number.

129141520 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 129141520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160000920).

129141520 is an abundant number, since it is smaller than the sum of its proper divisors (190860320).

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

129141520 is a wasteful number, since it uses less digits than its factorization.

129141520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 129141520 is about 11364.0450544689. The cubic root of 129141520 is about 505.4621394483.

The spelling of 129141520 in words is "one hundred twenty-nine million, one hundred forty-one thousand, five hundred twenty".