21822173 has 2 divisors, whose sum is σ = 21822174. Its totient is φ = 21822172.

The previous prime is 21822149. The next prime is 21822197. The reversal of 21822173 is 37122812.

It is a balanced prime because it is at equal distance from previous prime (21822149) and next prime (21822197).

It can be written as a sum of positive squares in only one way, i.e., 15155449 + 6666724 = 3893^2 + 2582^2 .

It is a cyclic number.

It is not a de Polignac number, because 21822173 - 2¹² = 21818077 is a prime.

It is a Sophie Germain 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 (21822103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10911086 + 10911087.

It is an arithmetic number, because the mean of its divisors is an integer number (10911087).

Almost surely, 2^21822173 is an apocalyptic number.

It is an amenable number.

21822173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21822173 is an equidigital number, since it uses as much as digits as its factorization.

21822173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 26.

The square root of 21822173 is about 4671.4208759220. The cubic root of 21822173 is about 279.4469226947.

Adding to 21822173 its reverse (37122812), we get a palindrome (58944985).

The spelling of 21822173 in words is "twenty-one million, eight hundred twenty-two thousand, one hundred seventy-three".