22420421 has 2 divisors, whose sum is σ = 22420422. Its totient is φ = 22420420.

The previous prime is 22420403. The next prime is 22420427. The reversal of 22420421 is 12402422.

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., 22420225 + 196 = 4735^2 + 14^2 .

It is a cyclic number.

It is not a de Polignac number, because 22420421 - 2⁶ = 22420357 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 22420421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22420427) 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, 11210210 + 11210211.

It is an arithmetic number, because the mean of its divisors is an integer number (11210211).

Almost surely, 2^22420421 is an apocalyptic number.

It is an amenable number.

22420421 is a deficient number, since it is larger than the sum of its proper divisors (1).

22420421 is an equidigital number, since it uses as much as digits as its factorization.

22420421 is an odious number, because the sum of its binary digits is odd.

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

The square root of 22420421 is about 4735.0206968925. The cubic root of 22420421 is about 281.9775856973.

Adding to 22420421 its reverse (12402422), we get a palindrome (34822843).

The spelling of 22420421 in words is "twenty-two million, four hundred twenty thousand, four hundred twenty-one".