181113217 has 2 divisors, whose sum is σ = 181113218. Its totient is φ = 181113216.

The previous prime is 181113203. The next prime is 181113239. The reversal of 181113217 is 712311181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106998336 + 74114881 = 10344^2 + 8609^2 .

It is an emirp because it is prime and its reverse (712311181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181113217 - 2⁷ = 181113089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 181113191 and 181113200.

It is not a weakly prime, because it can be changed into another prime (181113287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90556608 + 90556609.

It is an arithmetic number, because the mean of its divisors is an integer number (90556609).

Almost surely, 2^181113217 is an apocalyptic number.

It is an amenable number.

181113217 is a deficient number, since it is larger than the sum of its proper divisors (1).

181113217 is an equidigital number, since it uses as much as digits as its factorization.

181113217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 336, while the sum is 25.

The square root of 181113217 is about 13457.8310659630. The cubic root of 181113217 is about 565.7832007735.

Adding to 181113217 its reverse (712311181), we get a palindrome (893424398).

The spelling of 181113217 in words is "one hundred eighty-one million, one hundred thirteen thousand, two hundred seventeen".