18700117 has 2 divisors, whose sum is σ = 18700118. Its totient is φ = 18700116.

The previous prime is 18700103. The next prime is 18700163. The reversal of 18700117 is 71100781.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15634116 + 3066001 = 3954^2 + 1751^2 .

It is an emirp because it is prime and its reverse (71100781) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18700117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18700091 and 18700100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18700217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9350058 + 9350059.

It is an arithmetic number, because the mean of its divisors is an integer number (9350059).

Almost surely, 2^18700117 is an apocalyptic number.

It is an amenable number.

18700117 is a deficient number, since it is larger than the sum of its proper divisors (1).

18700117 is an equidigital number, since it uses as much as digits as its factorization.

18700117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 25.

The square root of 18700117 is about 4324.3631901125. The cubic root of 18700117 is about 265.4288392934.

Adding to 18700117 its reverse (71100781), we get a palindrome (89800898).

The spelling of 18700117 in words is "eighteen million, seven hundred thousand, one hundred seventeen".