66050209 has 2 divisors, whose sum is σ = 66050210. Its totient is φ = 66050208.

The previous prime is 66050207. The next prime is 66050249. The reversal of 66050209 is 90205066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65157184 + 893025 = 8072^2 + 945^2 .

It is a cyclic number.

It is not a de Polignac number, because 66050209 - 2¹ = 66050207 is a prime.

Together with 66050207, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66050203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33025104 + 33025105.

It is an arithmetic number, because the mean of its divisors is an integer number (33025105).

Almost surely, 2^66050209 is an apocalyptic number.

It is an amenable number.

66050209 is a deficient number, since it is larger than the sum of its proper divisors (1).

66050209 is an equidigital number, since it uses as much as digits as its factorization.

66050209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 66050209 is about 8127.1279674926. The cubic root of 66050209 is about 404.2264541777.

The spelling of 66050209 in words is "sixty-six million, fifty thousand, two hundred nine".