66984217 has 2 divisors, whose sum is σ = 66984218. Its totient is φ = 66984216.

The previous prime is 66984173. The next prime is 66984227. The reversal of 66984217 is 71248966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 50751376 + 16232841 = 7124^2 + 4029^2 .

It is a cyclic number.

It is not a de Polignac number, because 66984217 - 2⁷ = 66984089 is a prime.

It is not a weakly prime, because it can be changed into another prime (66984227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33492108 + 33492109.

It is an arithmetic number, because the mean of its divisors is an integer number (33492109).

Almost surely, 2^66984217 is an apocalyptic number.

It is an amenable number.

66984217 is a deficient number, since it is larger than the sum of its proper divisors (1).

66984217 is an equidigital number, since it uses as much as digits as its factorization.

66984217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 43.

The square root of 66984217 is about 8184.3886149180. The cubic root of 66984217 is about 406.1229152944.

The spelling of 66984217 in words is "sixty-six million, nine hundred eighty-four thousand, two hundred seventeen".