129131656 has 16 divisors (see below), whose sum is σ = 243130140. Its totient is φ = 64296960.

The previous prime is 129131641. The next prime is 129131659. The reversal of 129131656 is 656131921.

It can be written as a sum of positive squares in 2 ways, for example, as 124679556 + 4452100 = 11166^2 + 2110^2 .

It is not an unprimeable number, because it can be changed into a prime (129131659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31561 + ... + 35416.

Almost surely, 2^129131656 is an apocalyptic number.

It is an amenable number.

129131656 is a deficient number, since it is larger than the sum of its proper divisors (113998484).

129131656 is a wasteful number, since it uses less digits than its factorization.

129131656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67224 (or 67220 counting only the distinct ones).

The product of its digits is 9720, while the sum is 34.

The square root of 129131656 is about 11363.6110457900. The cubic root of 129131656 is about 505.4492698318.

The spelling of 129131656 in words is "one hundred twenty-nine million, one hundred thirty-one thousand, six hundred fifty-six".