129568381 has 2 divisors, whose sum is σ = 129568382. Its totient is φ = 129568380.

The previous prime is 129568367. The next prime is 129568421. The reversal of 129568381 is 183865921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119902500 + 9665881 = 10950^2 + 3109^2 .

It is an emirp because it is prime and its reverse (183865921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129568381 - 2⁷ = 129568253 is a prime.

It is a super-2 number, since 2×129568381² = 33575930709922322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129568181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64784190 + 64784191.

It is an arithmetic number, because the mean of its divisors is an integer number (64784191).

Almost surely, 2^129568381 is an apocalyptic number.

It is an amenable number.

129568381 is a deficient number, since it is larger than the sum of its proper divisors (1).

129568381 is an equidigital number, since it uses as much as digits as its factorization.

129568381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 103680, while the sum is 43.

The square root of 129568381 is about 11382.8107688743. The cubic root of 129568381 is about 506.0184407450.

The spelling of 129568381 in words is "one hundred twenty-nine million, five hundred sixty-eight thousand, three hundred eighty-one".