20422021 has 2 divisors, whose sum is σ = 20422022. Its totient is φ = 20422020.

The previous prime is 20422001. The next prime is 20422027. The reversal of 20422021 is 12022402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20349121 + 72900 = 4511^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 20422021 - 2¹⁹ = 19897733 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20421992 and 20422010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20422027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10211010 + 10211011.

It is an arithmetic number, because the mean of its divisors is an integer number (10211011).

Almost surely, 2^20422021 is an apocalyptic number.

It is an amenable number.

20422021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20422021 is an equidigital number, since it uses as much as digits as its factorization.

20422021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 20422021 is about 4519.0730244155. The cubic root of 20422021 is about 273.3377233415.

Adding to 20422021 its reverse (12022402), we get a palindrome (32444423).

The spelling of 20422021 in words is "twenty million, four hundred twenty-two thousand, twenty-one".