129916909 has 2 divisors, whose sum is σ = 129916910. Its totient is φ = 129916908.

The previous prime is 129916849. The next prime is 129916931. The reversal of 129916909 is 909619921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128187684 + 1729225 = 11322^2 + 1315^2 .

It is a cyclic number.

It is not a de Polignac number, because 129916909 - 2¹¹ = 129914861 is a prime.

It is a super-2 number, since 2×129916909² = 33756806488228562, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129916979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64958454 + 64958455.

It is an arithmetic number, because the mean of its divisors is an integer number (64958455).

Almost surely, 2^129916909 is an apocalyptic number.

It is an amenable number.

129916909 is a deficient number, since it is larger than the sum of its proper divisors (1).

129916909 is an equidigital number, since it uses as much as digits as its factorization.

129916909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 78732, while the sum is 46.

The square root of 129916909 is about 11398.1098871699. The cubic root of 129916909 is about 506.4717501534.

It can be divided in two parts, 12991 and 6909, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 129916909 in words is "one hundred twenty-nine million, nine hundred sixteen thousand, nine hundred nine".