20822281 has 2 divisors, whose sum is σ = 20822282. Its totient is φ = 20822280.

The previous prime is 20822279. The next prime is 20822287. The reversal of 20822281 is 18222802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 210681 = 4540^2 + 459^2 .

It is a cyclic number.

It is not a de Polignac number, because 20822281 - 2¹ = 20822279 is a prime.

It is a super-2 number, since 2×20822281² = 867134772085922, which contains 22 as substring.

Together with 20822279, it forms a pair of twin primes.

It is equal to p_1319416 and since 20822281 and 1319416 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20822287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10411140 + 10411141.

It is an arithmetic number, because the mean of its divisors is an integer number (10411141).

Almost surely, 2^20822281 is an apocalyptic number.

It is an amenable number.

20822281 is a deficient number, since it is larger than the sum of its proper divisors (1).

20822281 is an equidigital number, since it uses as much as digits as its factorization.

20822281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1024, while the sum is 25.

The square root of 20822281 is about 4563.1437628021. The cubic root of 20822281 is about 275.1119367999. Note that the first 3 decimals are identical.

The spelling of 20822281 in words is "twenty million, eight hundred twenty-two thousand, two hundred eighty-one".