20208217 has 2 divisors, whose sum is σ = 20208218. Its totient is φ = 20208216.

The previous prime is 20208163. The next prime is 20208241. The reversal of 20208217 is 71280202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19149376 + 1058841 = 4376^2 + 1029^2 .

It is a cyclic number.

It is not a de Polignac number, because 20208217 - 2¹¹ = 20206169 is a prime.

It is not a weakly prime, because it can be changed into another prime (20208247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10104108 + 10104109.

It is an arithmetic number, because the mean of its divisors is an integer number (10104109).

Almost surely, 2^20208217 is an apocalyptic number.

It is an amenable number.

20208217 is a deficient number, since it is larger than the sum of its proper divisors (1).

20208217 is an equidigital number, since it uses as much as digits as its factorization.

20208217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 20208217 is about 4495.3550471570. The cubic root of 20208217 is about 272.3804913207.

Adding to 20208217 its reverse (71280202), we get a palindrome (91488419).

The spelling of 20208217 in words is "twenty million, two hundred eight thousand, two hundred seventeen".