129423421440 has 312 divisors, whose sum is σ = 468133342560. Its totient is φ = 33011269632.

The previous prime is 129423421427. The next prime is 129423421441. The reversal of 129423421440 is 44124324921.

129423421440 is a `hidden beast` number, since 12 + 9 + 423 + 4 + 214 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 129423421395 and 129423421404.

It is not an unprimeable number, because it can be changed into a prime (129423421441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4224096 + ... + 4254624.

It is an arithmetic number, because the mean of its divisors is an integer number (1500427380).

Almost surely, 2^129423421440 is an apocalyptic number.

129423421440 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 129423421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234066671280).

129423421440 is an abundant number, since it is smaller than the sum of its proper divisors (338709921120).

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

129423421440 is a wasteful number, since it uses less digits than its factorization.

129423421440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30587 (or 30562 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 129423421440 in words is "one hundred twenty-nine billion, four hundred twenty-three million, four hundred twenty-one thousand, four hundred forty".