129439657 has 2 divisors, whose sum is σ = 129439658. Its totient is φ = 129439656.

The previous prime is 129439637. The next prime is 129439669. The reversal of 129439657 is 756934921.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110334016 + 19105641 = 10504^2 + 4371^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129439657 is a prime.

It is not a weakly prime, because it can be changed into another prime (129439637) 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, 64719828 + 64719829.

It is an arithmetic number, because the mean of its divisors is an integer number (64719829).

Almost surely, 2^129439657 is an apocalyptic number.

It is an amenable number.

129439657 is a deficient number, since it is larger than the sum of its proper divisors (1).

129439657 is an equidigital number, since it uses as much as digits as its factorization.

129439657 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 408240, while the sum is 46.

The square root of 129439657 is about 11377.1550486051. The cubic root of 129439657 is about 505.8508116267.

The spelling of 129439657 in words is "one hundred twenty-nine million, four hundred thirty-nine thousand, six hundred fifty-seven".