505550209 has 2 divisors, whose sum is σ = 505550210. Its totient is φ = 505550208.

The previous prime is 505550167. The next prime is 505550219. The reversal of 505550209 is 902055505.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 505350400 + 199809 = 22480^2 + 447^2 .

It is a cyclic number.

It is not a de Polignac number, because 505550209 - 2¹⁷ = 505419137 is a prime.

It is a super-3 number, since 3×505550209³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (505550219) 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, 252775104 + 252775105.

It is an arithmetic number, because the mean of its divisors is an integer number (252775105).

Almost surely, 2^505550209 is an apocalyptic number.

It is an amenable number.

505550209 is a deficient number, since it is larger than the sum of its proper divisors (1).

505550209 is an equidigital number, since it uses as much as digits as its factorization.

505550209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11250, while the sum is 31.

The square root of 505550209 is about 22484.4437111528. The cubic root of 505550209 is about 796.6265284618.

The spelling of 505550209 in words is "five hundred five million, five hundred fifty thousand, two hundred nine".