66047209 has 2 divisors, whose sum is σ = 66047210. Its totient is φ = 66047208.

The previous prime is 66047161. The next prime is 66047213. The reversal of 66047209 is 90274066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59721984 + 6325225 = 7728^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 66047209 - 2²¹ = 63950057 is a prime.

It is not a weakly prime, because it can be changed into another prime (66047279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33023604 + 33023605.

It is an arithmetic number, because the mean of its divisors is an integer number (33023605).

Almost surely, 2^66047209 is an apocalyptic number.

It is an amenable number.

66047209 is a deficient number, since it is larger than the sum of its proper divisors (1).

66047209 is an equidigital number, since it uses as much as digits as its factorization.

66047209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 34.

The square root of 66047209 is about 8126.9433983509. The cubic root of 66047209 is about 404.2203340976.

The spelling of 66047209 in words is "sixty-six million, forty-seven thousand, two hundred nine".