18700217 has 2 divisors, whose sum is σ = 18700218. Its totient is φ = 18700216.

The previous prime is 18700211. The next prime is 18700243. The reversal of 18700217 is 71200781.

It is an a-pointer prime, because the next prime (18700243) can be obtained adding 18700217 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18627856 + 72361 = 4316^2 + 269^2 .

It is an emirp because it is prime and its reverse (71200781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18700217 - 2¹⁸ = 18438073 is a prime.

It is not a weakly prime, because it can be changed into another prime (18700211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9350108 + 9350109.

It is an arithmetic number, because the mean of its divisors is an integer number (9350109).

Almost surely, 2^18700217 is an apocalyptic number.

It is an amenable number.

18700217 is a deficient number, since it is larger than the sum of its proper divisors (1).

18700217 is an equidigital number, since it uses as much as digits as its factorization.

18700217 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 784, while the sum is 26.

The square root of 18700217 is about 4324.3747524931. The cubic root of 18700217 is about 265.4293124248.

Adding to 18700217 its reverse (71200781), we get a palindrome (89900998).

The spelling of 18700217 in words is "eighteen million, seven hundred thousand, two hundred seventeen".