129088585521 has 63 divisors (see below), whose sum is σ = 225261912603. Its totient is φ = 73726102800.

The previous prime is 129088585511. The next prime is 129088585643. The reversal of 129088585521 is 125585880921.

The square root of 129088585521 is 359289.

It is a perfect power (a square), and thus also a powerful number.

129088585521 is a `hidden beast` number, since 1 + 2 + 9 + 0 + 8 + 8 + 585 + 52 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10766345121 + 118322240400 = 103761^2 + 343980^2 .

It is a tau number, because it is divible by the number of its divisors (63).

It is not a de Polignac number, because 129088585521 - 2²³ = 129080196913 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (129088585511) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 67904671 + ... + 67906571.

Almost surely, 2^129088585521 is an apocalyptic number.

129088585521 is the 359289-th square number.

129088585521 is the 179645-th centered octagonal number.

It is an amenable number.

129088585521 is a deficient number, since it is larger than the sum of its proper divisors (96173327082).

129088585521 is an frugal number, since it uses more digits than its factorization.

129088585521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3834 (or 1911 counting only the distinct ones).

The product of its (nonzero) digits is 2304000, while the sum is 54.

The spelling of 129088585521 in words is "one hundred twenty-nine billion, eighty-eight million, five hundred eighty-five thousand, five hundred twenty-one".