18116281 has 2 divisors, whose sum is σ = 18116282. Its totient is φ = 18116280.

The previous prime is 18116261. The next prime is 18116311. The reversal of 18116281 is 18261181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12138256 + 5978025 = 3484^2 + 2445^2 .

It is an emirp because it is prime and its reverse (18261181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18116281 - 2¹³ = 18108089 is a prime.

It is a super-2 number, since 2×18116281² = 656399274541922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18116251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9058140 + 9058141.

It is an arithmetic number, because the mean of its divisors is an integer number (9058141).

Almost surely, 2^18116281 is an apocalyptic number.

It is an amenable number.

18116281 is a deficient number, since it is larger than the sum of its proper divisors (1).

18116281 is an equidigital number, since it uses as much as digits as its factorization.

18116281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 768, while the sum is 28.

The square root of 18116281 is about 4256.3224736855. The cubic root of 18116281 is about 262.6372663790.

The spelling of 18116281 in words is "eighteen million, one hundred sixteen thousand, two hundred eighty-one".