18221282 has 4 divisors (see below), whose sum is σ = 27331926. Its totient is φ = 9110640.

The previous prime is 18221257. The next prime is 18221339. The reversal of 18221282 is 28212281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28212281 = 83 ⋅339907.

It can be written as a sum of positive squares in only one way, i.e., 18054001 + 167281 = 4249^2 + 409^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4555319 + ... + 4555322.

Almost surely, 2^18221282 is an apocalyptic number.

18221282 is a deficient number, since it is larger than the sum of its proper divisors (9110644).

18221282 is an equidigital number, since it uses as much as digits as its factorization.

18221282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9110643.

The product of its digits is 1024, while the sum is 26.

The square root of 18221282 is about 4268.6393616702. The cubic root of 18221282 is about 263.1436997522.

Subtracting 18221282 from its reverse (28212281), we obtain a palindrome (9990999).

The spelling of 18221282 in words is "eighteen million, two hundred twenty-one thousand, two hundred eighty-two".