129008261 has 2 divisors, whose sum is σ = 129008262. Its totient is φ = 129008260.

The previous prime is 129008183. The next prime is 129008273. The reversal of 129008261 is 162800921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128822500 + 185761 = 11350^2 + 431^2 .

It is an emirp because it is prime and its reverse (162800921) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129008261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129004261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64504130 + 64504131.

It is an arithmetic number, because the mean of its divisors is an integer number (64504131).

Almost surely, 2^129008261 is an apocalyptic number.

It is an amenable number.

129008261 is a deficient number, since it is larger than the sum of its proper divisors (1).

129008261 is an equidigital number, since it uses as much as digits as its factorization.

129008261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 129008261 is about 11358.1803560253. The cubic root of 129008261 is about 505.2882202707.

The spelling of 129008261 in words is "one hundred twenty-nine million, eight thousand, two hundred sixty-one".