505564991 has 2 divisors, whose sum is σ = 505564992. Its totient is φ = 505564990.

The previous prime is 505564987. The next prime is 505565059. The reversal of 505564991 is 199465505.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 505564991 - 2² = 505564987 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (505564951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 252782495 + 252782496.

It is an arithmetic number, because the mean of its divisors is an integer number (252782496).

Almost surely, 2^505564991 is an apocalyptic number.

505564991 is a deficient number, since it is larger than the sum of its proper divisors (1).

505564991 is an equidigital number, since it uses as much as digits as its factorization.

505564991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243000, while the sum is 44.

The square root of 505564991 is about 22484.7724249102. The cubic root of 505564991 is about 796.6342926880.

The spelling of 505564991 in words is "five hundred five million, five hundred sixty-four thousand, nine hundred ninety-one".