18822581 has 2 divisors, whose sum is σ = 18822582. Its totient is φ = 18822580.

The previous prime is 18822571. The next prime is 18822599. The reversal of 18822581 is 18522881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 4268356 = 3815^2 + 2066^2 .

It is a cyclic number.

It is not a de Polignac number, because 18822581 - 2¹⁴ = 18806197 is a prime.

It is a super-2 number, since 2×18822581² = 708579111003122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18822571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9411290 + 9411291.

It is an arithmetic number, because the mean of its divisors is an integer number (9411291).

Almost surely, 2^18822581 is an apocalyptic number.

It is an amenable number.

18822581 is a deficient number, since it is larger than the sum of its proper divisors (1).

18822581 is an equidigital number, since it uses as much as digits as its factorization.

18822581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10240, while the sum is 35.

The square root of 18822581 is about 4338.4998559410. The cubic root of 18822581 is about 266.0069956892.

The spelling of 18822581 in words is "eighteen million, eight hundred twenty-two thousand, five hundred eighty-one".