129138742656 has 1152 divisors, whose sum is σ = 495918696000. Its totient is φ = 32188907520.

The previous prime is 129138742633. The next prime is 129138742657. The reversal of 129138742656 is 656247831921.

It is a happy number.

129138742656 is a `hidden beast` number, since 1 + 2 + 91 + 3 + 87 + 426 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129138742657) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1769023836 + ... + 1769023908.

Almost surely, 2^129138742656 is an apocalyptic number.

129138742656 is a gapful number since it is divisible by the number (16) 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 129138742656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (247959348000).

129138742656 is an abundant number, since it is smaller than the sum of its proper divisors (366779953344).

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

129138742656 is a wasteful number, since it uses less digits than its factorization.

129138742656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 133 counting only the distinct ones).

The product of its digits is 4354560, while the sum is 54.

The spelling of 129138742656 in words is "one hundred twenty-nine billion, one hundred thirty-eight million, seven hundred forty-two thousand, six hundred fifty-six".