129559956820 has 24 divisors (see below), whose sum is σ = 310943896704. Its totient is φ = 44420556576.

The previous prime is 129559956751. The next prime is 129559956821. The reversal of 129559956820 is 28659955921.

129559956820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×129559956820² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129559956821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 462713992 + ... + 462714271.

It is an arithmetic number, because the mean of its divisors is an integer number (12955995696).

Almost surely, 2^129559956820 is an apocalyptic number.

129559956820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129559956820 is an abundant number, since it is smaller than the sum of its proper divisors (181383939884).

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

129559956820 is a wasteful number, since it uses less digits than its factorization.

129559956820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925428279 (or 925428277 counting only the distinct ones).

The product of its (nonzero) digits is 17496000, while the sum is 61.

The spelling of 129559956820 in words is "one hundred twenty-nine billion, five hundred fifty-nine million, nine hundred fifty-six thousand, eight hundred twenty".