129656256 has 56 divisors (see below), whose sum is σ = 348203520. Its totient is φ = 42569472.

The previous prime is 129656239. The next prime is 129656269. The reversal of 129656256 is 652656921.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7825 + ... + 17903.

It is an arithmetic number, because the mean of its divisors is an integer number (6217920).

Almost surely, 2^129656256 is an apocalyptic number.

129656256 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 129656256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174101760).

129656256 is an abundant number, since it is smaller than the sum of its proper divisors (218547264).

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

129656256 is a wasteful number, since it uses less digits than its factorization.

129656256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10161 (or 10151 counting only the distinct ones).

The product of its digits is 194400, while the sum is 42.

The square root of 129656256 is about 11386.6701014827. The cubic root of 129656256 is about 506.1328110396.

The spelling of 129656256 in words is "one hundred twenty-nine million, six hundred fifty-six thousand, two hundred fifty-six".