9780217 has 2 divisors, whose sum is σ = 9780218. Its totient is φ = 9780216.

The previous prime is 9780203. The next prime is 9780227. The reversal of 9780217 is 7120879.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9114361 + 665856 = 3019^2 + 816^2 .

It is an emirp because it is prime and its reverse (7120879) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9780217 is a prime.

9780217 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (9780227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4890108 + 4890109.

It is an arithmetic number, because the mean of its divisors is an integer number (4890109).

Almost surely, 2^9780217 is an apocalyptic number.

It is an amenable number.

9780217 is a deficient number, since it is larger than the sum of its proper divisors (1).

9780217 is an equidigital number, since it uses as much as digits as its factorization.

9780217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 9780217 is about 3127.3338485042. Note that the first 3 decimals coincide. The cubic root of 9780217 is about 213.8534020872.

The spelling of 9780217 in words is "nine million, seven hundred eighty thousand, two hundred seventeen".