129705556218 has 64 divisors (see below), whose sum is σ = 312531747840. Its totient is φ = 35056720512.

The previous prime is 129705556213. The next prime is 129705556229. The reversal of 129705556218 is 812655507921.

It is not an unprimeable number, because it can be changed into a prime (129705556213) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 426046 + ... + 664022.

It is an arithmetic number, because the mean of its divisors is an integer number (4883308560).

Almost surely, 2^129705556218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129705556218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156265873920).

129705556218 is an abundant number, since it is smaller than the sum of its proper divisors (182826191622).

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

129705556218 is a wasteful number, since it uses less digits than its factorization.

129705556218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238691.

The product of its (nonzero) digits is 1512000, while the sum is 51.

The spelling of 129705556218 in words is "one hundred twenty-nine billion, seven hundred five million, five hundred fifty-six thousand, two hundred eighteen".