20622821 has 2 divisors, whose sum is σ = 20622822. Its totient is φ = 20622820.

The previous prime is 20622803. The next prime is 20622827. The reversal of 20622821 is 12822602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14546596 + 6076225 = 3814^2 + 2465^2 .

It is a cyclic number.

It is not a de Polignac number, because 20622821 - 2¹⁸ = 20360677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20622827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10311410 + 10311411.

It is an arithmetic number, because the mean of its divisors is an integer number (10311411).

Almost surely, 2^20622821 is an apocalyptic number.

It is an amenable number.

20622821 is a deficient number, since it is larger than the sum of its proper divisors (1).

20622821 is an equidigital number, since it uses as much as digits as its factorization.

20622821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 20622821 is about 4541.2356248052. The cubic root of 20622821 is about 274.2306695898.

The spelling of 20622821 in words is "twenty million, six hundred twenty-two thousand, eight hundred twenty-one".