18444281 has 2 divisors, whose sum is σ = 18444282. Its totient is φ = 18444280.

The previous prime is 18444247. The next prime is 18444289. The reversal of 18444281 is 18244481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15523600 + 2920681 = 3940^2 + 1709^2 .

It is a cyclic number.

It is not a de Polignac number, because 18444281 - 2¹⁴ = 18427897 is a prime.

It is a super-2 number, since 2×18444281² = 680383003213922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18444289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9222140 + 9222141.

It is an arithmetic number, because the mean of its divisors is an integer number (9222141).

Almost surely, 2^18444281 is an apocalyptic number.

It is an amenable number.

18444281 is a deficient number, since it is larger than the sum of its proper divisors (1).

18444281 is an equidigital number, since it uses as much as digits as its factorization.

18444281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8192, while the sum is 32.

The square root of 18444281 is about 4294.6805469092. The cubic root of 18444281 is about 264.2128343758.

The spelling of 18444281 in words is "eighteen million, four hundred forty-four thousand, two hundred eighty-one".