129504509820 has 216 divisors, whose sum is σ = 458660599488. Its totient is φ = 29491257600.

The previous prime is 129504509809. The next prime is 129504509857. The reversal of 129504509820 is 28905405921.

It is a happy number.

129504509820 is a `hidden beast` number, since 1 + 2 + 9 + 504 + 50 + 98 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2363130 + ... + 2417310.

Almost surely, 2^129504509820 is an apocalyptic number.

129504509820 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 129504509820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229330299744).

129504509820 is an abundant number, since it is smaller than the sum of its proper divisors (329156089668).

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

129504509820 is a wasteful number, since it uses less digits than its factorization.

129504509820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54481 (or 54469 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 129504509820 in words is "one hundred twenty-nine billion, five hundred four million, five hundred nine thousand, eight hundred twenty".