66219449 has 2 divisors, whose sum is σ = 66219450. Its totient is φ = 66219448.

The previous prime is 66219443. The next prime is 66219457. The reversal of 66219449 is 94491266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44129449 + 22090000 = 6643^2 + 4700^2 .

It is a cyclic number.

It is not a de Polignac number, because 66219449 - 2¹² = 66215353 is a prime.

It is not a weakly prime, because it can be changed into another prime (66219443) 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, 33109724 + 33109725.

It is an arithmetic number, because the mean of its divisors is an integer number (33109725).

Almost surely, 2^66219449 is an apocalyptic number.

It is an amenable number.

66219449 is a deficient number, since it is larger than the sum of its proper divisors (1).

66219449 is an equidigital number, since it uses as much as digits as its factorization.

66219449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 41.

The square root of 66219449 is about 8137.5333486260. The cubic root of 66219449 is about 404.5714086159.

The spelling of 66219449 in words is "sixty-six million, two hundred nineteen thousand, four hundred forty-nine".