18162281 has 2 divisors, whose sum is σ = 18162282. Its totient is φ = 18162280.

The previous prime is 18162269. The next prime is 18162283. The reversal of 18162281 is 18226181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 2202256 = 3995^2 + 1484^2 .

It is a cyclic number.

It is not a de Polignac number, because 18162281 - 2⁶ = 18162217 is a prime.

It is a super-2 number, since 2×18162281² = 659736902245922, which contains 22 as substring.

Together with 18162283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18162283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9081140 + 9081141.

It is an arithmetic number, because the mean of its divisors is an integer number (9081141).

Almost surely, 2^18162281 is an apocalyptic number.

It is an amenable number.

18162281 is a deficient number, since it is larger than the sum of its proper divisors (1).

18162281 is an equidigital number, since it uses as much as digits as its factorization.

18162281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1536, while the sum is 29.

The square root of 18162281 is about 4261.7227737149. The cubic root of 18162281 is about 262.8593705225.

The spelling of 18162281 in words is "eighteen million, one hundred sixty-two thousand, two hundred eighty-one".