66403217 has 2 divisors, whose sum is σ = 66403218. Its totient is φ = 66403216.

The previous prime is 66403199. The next prime is 66403229. The reversal of 66403217 is 71230466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42627841 + 23775376 = 6529^2 + 4876^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66403217 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66403217.

It is not a weakly prime, because it can be changed into another prime (66403297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33201608 + 33201609.

It is an arithmetic number, because the mean of its divisors is an integer number (33201609).

Almost surely, 2^66403217 is an apocalyptic number.

It is an amenable number.

66403217 is a deficient number, since it is larger than the sum of its proper divisors (1).

66403217 is an equidigital number, since it uses as much as digits as its factorization.

66403217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 66403217 is about 8148.8169079935. The cubic root of 66403217 is about 404.9453098940.

The spelling of 66403217 in words is "sixty-six million, four hundred three thousand, two hundred seventeen".