422420021 has 2 divisors, whose sum is σ = 422420022. Its totient is φ = 422420020.

The previous prime is 422419997. The next prime is 422420039. The reversal of 422420021 is 120024224.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253159921 + 169260100 = 15911^2 + 13010^2 .

It is a cyclic number.

It is not a de Polignac number, because 422420021 - 2⁶ = 422419957 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 (422420051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 211210010 + 211210011.

It is an arithmetic number, because the mean of its divisors is an integer number (211210011).

Almost surely, 2^422420021 is an apocalyptic number.

It is an amenable number.

422420021 is a deficient number, since it is larger than the sum of its proper divisors (1).

422420021 is an equidigital number, since it uses as much as digits as its factorization.

422420021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 422420021 is about 20552.8591928228. The cubic root of 422420021 is about 750.3228364230.

Adding to 422420021 its reverse (120024224), we get a palindrome (542444245).

The spelling of 422420021 in words is "four hundred twenty-two million, four hundred twenty thousand, twenty-one".