129256220418 has 32 divisors (see below), whose sum is σ = 278412253056. Its totient is φ = 39769110528.

The previous prime is 129256220417. The next prime is 129256220441. The reversal of 129256220418 is 814022652921.

129256220418 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 129256220418.

It is not an unprimeable number, because it can be changed into a prime (129256220417) 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, 2359171 + ... + 2413337.

It is an arithmetic number, because the mean of its divisors is an integer number (8700382908).

Almost surely, 2^129256220418 is an apocalyptic number.

129256220418 is an abundant number, since it is smaller than the sum of its proper divisors (149156032638).

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

129256220418 is a wasteful number, since it uses less digits than its factorization.

129256220418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84778.

The product of its (nonzero) digits is 138240, while the sum is 42.

The spelling of 129256220418 in words is "one hundred twenty-nine billion, two hundred fifty-six million, two hundred twenty thousand, four hundred eighteen".