18882221 has 2 divisors, whose sum is σ = 18882222. Its totient is φ = 18882220.

The previous prime is 18882217. The next prime is 18882293. The reversal of 18882221 is 12228881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15602500 + 3279721 = 3950^2 + 1811^2 .

It is a cyclic number.

It is not a de Polignac number, because 18882221 - 2² = 18882217 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18882421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9441110 + 9441111.

It is an arithmetic number, because the mean of its divisors is an integer number (9441111).

Almost surely, 2^18882221 is an apocalyptic number.

It is an amenable number.

18882221 is a deficient number, since it is larger than the sum of its proper divisors (1).

18882221 is an equidigital number, since it uses as much as digits as its factorization.

18882221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4096, while the sum is 32.

The square root of 18882221 is about 4345.3677634925. The cubic root of 18882221 is about 266.2876502701.

The spelling of 18882221 in words is "eighteen million, eight hundred eighty-two thousand, two hundred twenty-one".