66372217 has 2 divisors, whose sum is σ = 66372218. Its totient is φ = 66372216.

The previous prime is 66372197. The next prime is 66372239. The reversal of 66372217 is 71227366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56010256 + 10361961 = 7484^2 + 3219^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66372217 is a prime.

It is not a weakly prime, because it can be changed into another prime (66372287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33186108 + 33186109.

It is an arithmetic number, because the mean of its divisors is an integer number (33186109).

Almost surely, 2^66372217 is an apocalyptic number.

It is an amenable number.

66372217 is a deficient number, since it is larger than the sum of its proper divisors (1).

66372217 is an equidigital number, since it uses as much as digits as its factorization.

66372217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 34.

The square root of 66372217 is about 8146.9145693324. The cubic root of 66372217 is about 404.8822845409.

The spelling of 66372217 in words is "sixty-six million, three hundred seventy-two thousand, two hundred seventeen".