908138809 has 2 divisors, whose sum is σ = 908138810. Its totient is φ = 908138808.

The previous prime is 908138753. The next prime is 908138843. The reversal of 908138809 is 908831809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 786522025 + 121616784 = 28045^2 + 11028^2 .

It is a cyclic number.

It is not a de Polignac number, because 908138809 - 2⁷ = 908138681 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (908138879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454069404 + 454069405.

It is an arithmetic number, because the mean of its divisors is an integer number (454069405).

Almost surely, 2^908138809 is an apocalyptic number.

It is an amenable number.

908138809 is a deficient number, since it is larger than the sum of its proper divisors (1).

908138809 is an equidigital number, since it uses as much as digits as its factorization.

908138809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 908138809 is about 30135.3415278473. The cubic root of 908138809 is about 968.3910013585.

The spelling of 908138809 in words is "nine hundred eight million, one hundred thirty-eight thousand, eight hundred nine".