129808891 has 2 divisors, whose sum is σ = 129808892. Its totient is φ = 129808890.

The previous prime is 129808853. The next prime is 129808907. The reversal of 129808891 is 198808921.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129808891 is a prime.

It is not a weakly prime, because it can be changed into another prime (129808801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64904445 + 64904446.

It is an arithmetic number, because the mean of its divisors is an integer number (64904446).

Almost surely, 2^129808891 is an apocalyptic number.

129808891 is a deficient number, since it is larger than the sum of its proper divisors (1).

129808891 is an equidigital number, since it uses as much as digits as its factorization.

129808891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 46.

The square root of 129808891 is about 11393.3704846283. The cubic root of 129808891 is about 506.3313444252.

The spelling of 129808891 in words is "one hundred twenty-nine million, eight hundred eight thousand, eight hundred ninety-one".