20001217 has 2 divisors, whose sum is σ = 20001218. Its totient is φ = 20001216.

The previous prime is 20001203. The next prime is 20001227. The reversal of 20001217 is 71210002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13830961 + 6170256 = 3719^2 + 2484^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001197 and 20001206.

It is not a weakly prime, because it can be changed into another prime (20001227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000608 + 10000609.

It is an arithmetic number, because the mean of its divisors is an integer number (10000609).

Almost surely, 2^20001217 is an apocalyptic number.

It is an amenable number.

20001217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001217 is an equidigital number, since it uses as much as digits as its factorization.

20001217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 20001217 is about 4472.2720176662. The cubic root of 20001217 is about 271.4472672916.

Adding to 20001217 its reverse (71210002), we get a palindrome (91211219).

The spelling of 20001217 in words is "twenty million, one thousand, two hundred seventeen".