129391817029 has 2 divisors, whose sum is σ = 129391817030. Its totient is φ = 129391817028.

The previous prime is 129391817003. The next prime is 129391817059. The reversal of 129391817029 is 920718193921.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126497592225 + 2894224804 = 355665^2 + 53798^2 .

It is a cyclic number.

It is not a de Polignac number, because 129391817029 - 2²⁵ = 129358262597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129391817059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64695908514 + 64695908515.

It is an arithmetic number, because the mean of its divisors is an integer number (64695908515).

Almost surely, 2^129391817029 is an apocalyptic number.

It is an amenable number.

129391817029 is a deficient number, since it is larger than the sum of its proper divisors (1).

129391817029 is an equidigital number, since it uses as much as digits as its factorization.

129391817029 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 52.

The spelling of 129391817029 in words is "one hundred twenty-nine billion, three hundred ninety-one million, eight hundred seventeen thousand, twenty-nine".