66206617 has 2 divisors, whose sum is σ = 66206618. Its totient is φ = 66206616.

The previous prime is 66206603. The next prime is 66206639. The reversal of 66206617 is 71660266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53275401 + 12931216 = 7299^2 + 3596^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66206617 is a prime.

It is a super-2 number, since 2×66206617² = 8766632269169378, which contains 22 as substring.

It is equal to p_3907654 and since 66206617 and 3907654 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66206417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33103308 + 33103309.

It is an arithmetic number, because the mean of its divisors is an integer number (33103309).

Almost surely, 2^66206617 is an apocalyptic number.

It is an amenable number.

66206617 is a deficient number, since it is larger than the sum of its proper divisors (1).

66206617 is an equidigital number, since it uses as much as digits as its factorization.

66206617 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 66206617 is about 8136.7448651165. The cubic root of 66206617 is about 404.5452743217.

The spelling of 66206617 in words is "sixty-six million, two hundred six thousand, six hundred seventeen".