129670909 has 2 divisors, whose sum is σ = 129670910. Its totient is φ = 129670908.

The previous prime is 129670907. The next prime is 129670949. The reversal of 129670909 is 909076921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 116165284 + 13505625 = 10778^2 + 3675^2 .

It is a cyclic number.

It is not a de Polignac number, because 129670909 - 2¹ = 129670907 is a prime.

Together with 129670907, it forms a pair of twin primes.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129670907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64835454 + 64835455.

It is an arithmetic number, because the mean of its divisors is an integer number (64835455).

Almost surely, 2^129670909 is an apocalyptic number.

It is an amenable number.

129670909 is a deficient number, since it is larger than the sum of its proper divisors (1).

129670909 is an equidigital number, since it uses as much as digits as its factorization.

129670909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 43.

The square root of 129670909 is about 11387.3135110965. The cubic root of 129670909 is about 506.1518770555.

The spelling of 129670909 in words is "one hundred twenty-nine million, six hundred seventy thousand, nine hundred nine".