129442656 has 96 divisors (see below), whose sum is σ = 393942528. Its totient is φ = 36449280.

The previous prime is 129442609. The next prime is 129442657. The reversal of 129442656 is 656244921.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129442657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46356 + ... + 49068.

It is an arithmetic number, because the mean of its divisors is an integer number (4103568).

Almost surely, 2^129442656 is an apocalyptic number.

129442656 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 129442656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196971264).

129442656 is an abundant number, since it is smaller than the sum of its proper divisors (264499872).

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

129442656 is a wasteful number, since it uses less digits than its factorization.

129442656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2804 (or 2796 counting only the distinct ones).

The product of its digits is 103680, while the sum is 39.

The square root of 129442656 is about 11377.2868470475. The cubic root of 129442656 is about 505.8547182987.

The spelling of 129442656 in words is "one hundred twenty-nine million, four hundred forty-two thousand, six hundred fifty-six".