129386261 has 2 divisors, whose sum is σ = 129386262. Its totient is φ = 129386260.

The previous prime is 129386239. The next prime is 129386291. The reversal of 129386261 is 162683921.

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., 90136036 + 39250225 = 9494^2 + 6265^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129386261 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129386291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64693130 + 64693131.

It is an arithmetic number, because the mean of its divisors is an integer number (64693131).

Almost surely, 2^129386261 is an apocalyptic number.

It is an amenable number.

129386261 is a deficient number, since it is larger than the sum of its proper divisors (1).

129386261 is an equidigital number, since it uses as much as digits as its factorization.

129386261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 38.

The square root of 129386261 is about 11374.8081742067. The cubic root of 129386261 is about 505.7812447837.

The spelling of 129386261 in words is "one hundred twenty-nine million, three hundred eighty-six thousand, two hundred sixty-one".