55317809 has 2 divisors, whose sum is σ = 55317810. Its totient is φ = 55317808.

The previous prime is 55317803. The next prime is 55317811. The reversal of 55317809 is 90871355.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52417600 + 2900209 = 7240^2 + 1703^2 .

It is a cyclic number.

It is not a de Polignac number, because 55317809 - 2²⁰ = 54269233 is a prime.

It is a Sophie Germain prime.

Together with 55317811, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (55317803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27658904 + 27658905.

It is an arithmetic number, because the mean of its divisors is an integer number (27658905).

Almost surely, 2^55317809 is an apocalyptic number.

It is an amenable number.

55317809 is a deficient number, since it is larger than the sum of its proper divisors (1).

55317809 is an equidigital number, since it uses as much as digits as its factorization.

55317809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 55317809 is about 7437.5943019232. The cubic root of 55317809 is about 381.0263321587.

The spelling of 55317809 in words is "fifty-five million, three hundred seventeen thousand, eight hundred nine".