129217777920 has 2592 divisors, whose sum is σ = 641222749440. Its totient is φ = 23357030400.

The previous prime is 129217777891. The next prime is 129217777981. The reversal of 129217777920 is 29777712921.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 3151653100 + ... + 3151653140.

It is an arithmetic number, because the mean of its divisors is an integer number (247385320).

Almost surely, 2^129217777920 is an apocalyptic number.

129217777920 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 129217777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (320611374720).

129217777920 is an abundant number, since it is smaller than the sum of its proper divisors (512004971520).

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

129217777920 is a wasteful number, since it uses less digits than its factorization.

129217777920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 1555848, while the sum is 54.

The spelling of 129217777920 in words is "one hundred twenty-nine billion, two hundred seventeen million, seven hundred seventy-seven thousand, nine hundred twenty".