129220081 has 2 divisors, whose sum is σ = 129220082. Its totient is φ = 129220080.

The previous prime is 129220073. The next prime is 129220097. The reversal of 129220081 is 180022921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120099681 + 9120400 = 10959^2 + 3020^2 .

It is a cyclic number.

It is not a de Polignac number, because 129220081 - 2³ = 129220073 is a prime.

It is a super-2 number, since 2×129220081² = 33395658667293122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129220981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64610040 + 64610041.

It is an arithmetic number, because the mean of its divisors is an integer number (64610041).

Almost surely, 2^129220081 is an apocalyptic number.

It is an amenable number.

129220081 is a deficient number, since it is larger than the sum of its proper divisors (1).

129220081 is an equidigital number, since it uses as much as digits as its factorization.

129220081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 129220081 is about 11367.5010886298. The cubic root of 129220081 is about 505.5646150416.

The spelling of 129220081 in words is "one hundred twenty-nine million, two hundred twenty thousand, eighty-one".