129012791638 has 16 divisors (see below), whose sum is σ = 195058558800. Its totient is φ = 63994341600.

The previous prime is 129012791627. The next prime is 129012791639. The reversal of 129012791638 is 836197210921.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 129012791591 and 129012791600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129012791639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25233 + ... + 508588.

It is an arithmetic number, because the mean of its divisors is an integer number (12191159925).

Almost surely, 2^129012791638 is an apocalyptic number.

129012791638 is a deficient number, since it is larger than the sum of its proper divisors (66045767162).

129012791638 is a wasteful number, since it uses less digits than its factorization.

129012791638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534783.

The product of its (nonzero) digits is 326592, while the sum is 49.

The spelling of 129012791638 in words is "one hundred twenty-nine billion, twelve million, seven hundred ninety-one thousand, six hundred thirty-eight".