129047656 has 8 divisors (see below), whose sum is σ = 241964370. Its totient is φ = 64523824.

The previous prime is 129047617. The next prime is 129047657. The reversal of 129047656 is 656740921.

It can be written as a sum of positive squares in only one way, i.e., 124679556 + 4368100 = 11166^2 + 2090^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (129047657) 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 as a sum of consecutive naturals, namely, 8065471 + ... + 8065486.

Almost surely, 2^129047656 is an apocalyptic number.

It is an amenable number.

129047656 is a deficient number, since it is larger than the sum of its proper divisors (112916714).

129047656 is a wasteful number, since it uses less digits than its factorization.

129047656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16130963 (or 16130959 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 129047656 is about 11359.9144362975. The cubic root of 129047656 is about 505.3396479943.

The spelling of 129047656 in words is "one hundred twenty-nine million, forty-seven thousand, six hundred fifty-six".