129028240 has 80 divisors (see below), whose sum is σ = 344531520. Its totient is φ = 44444160.

The previous prime is 129028199. The next prime is 129028247. The reversal of 129028240 is 42820921.

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

It is a junction number, because it is equal to n+sod(n) for n = 129028199 and 129028208.

It is not an unprimeable number, because it can be changed into a prime (129028247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12862 + ... + 20578.

It is an arithmetic number, because the mean of its divisors is an integer number (4306644).

Almost surely, 2^129028240 is an apocalyptic number.

129028240 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 129028240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172265760).

129028240 is an abundant number, since it is smaller than the sum of its proper divisors (215503280).

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

129028240 is a wasteful number, since it uses less digits than its factorization.

129028240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7760 (or 7754 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 129028240 is about 11359.0598202492. The cubic root of 129028240 is about 505.3143029215.

The spelling of 129028240 in words is "one hundred twenty-nine million, twenty-eight thousand, two hundred forty".