505647689 has 2 divisors, whose sum is σ = 505647690. Its totient is φ = 505647688.

The previous prime is 505647673. The next prime is 505647691. The reversal of 505647689 is 986746505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 452838400 + 52809289 = 21280^2 + 7267^2 .

It is a cyclic number.

It is not a de Polignac number, because 505647689 - 2⁴ = 505647673 is a prime.

It is a Sophie Germain prime.

Together with 505647691, 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 (505640689) 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, 252823844 + 252823845.

It is an arithmetic number, because the mean of its divisors is an integer number (252823845).

Almost surely, 2^505647689 is an apocalyptic number.

It is an amenable number.

505647689 is a deficient number, since it is larger than the sum of its proper divisors (1).

505647689 is an equidigital number, since it uses as much as digits as its factorization.

505647689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1814400, while the sum is 50.

The square root of 505647689 is about 22486.6113276323. The cubic root of 505647689 is about 796.6777269132.

The spelling of 505647689 in words is "five hundred five million, six hundred forty-seven thousand, six hundred eighty-nine".