129855832121 has 2 divisors, whose sum is σ = 129855832122. Its totient is φ = 129855832120.

The previous prime is 129855832061. The next prime is 129855832123. The reversal of 129855832121 is 121238558921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116851850896 + 13003981225 = 341836^2 + 114035^2 .

It is a cyclic number.

It is not a de Polignac number, because 129855832121 - 2¹⁰ = 129855831097 is a prime.

Together with 129855832123, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129855832123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64927916060 + 64927916061.

It is an arithmetic number, because the mean of its divisors is an integer number (64927916061).

Almost surely, 2^129855832121 is an apocalyptic number.

It is an amenable number.

129855832121 is a deficient number, since it is larger than the sum of its proper divisors (1).

129855832121 is an equidigital number, since it uses as much as digits as its factorization.

129855832121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 47.

The spelling of 129855832121 in words is "one hundred twenty-nine billion, eight hundred fifty-five million, eight hundred thirty-two thousand, one hundred twenty-one".