129909841 has 2 divisors, whose sum is σ = 129909842. Its totient is φ = 129909840.

The previous prime is 129909827. The next prime is 129909847. The reversal of 129909841 is 148909921.

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., 97930816 + 31979025 = 9896^2 + 5655^2 .

It is a cyclic number.

It is not a de Polignac number, because 129909841 - 2⁷ = 129909713 is a prime.

It is not a weakly prime, because it can be changed into another prime (129909847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64954920 + 64954921.

It is an arithmetic number, because the mean of its divisors is an integer number (64954921).

Almost surely, 2^129909841 is an apocalyptic number.

It is an amenable number.

129909841 is a deficient number, since it is larger than the sum of its proper divisors (1).

129909841 is an equidigital number, since it uses as much as digits as its factorization.

129909841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 129909841 is about 11397.7998315464. The cubic root of 129909841 is about 506.4625652898.

The spelling of 129909841 in words is "one hundred twenty-nine million, nine hundred nine thousand, eight hundred forty-one".