426221021 has 2 divisors, whose sum is σ = 426221022. Its totient is φ = 426221020.

The previous prime is 426221011. The next prime is 426221041. The reversal of 426221021 is 120122624.

It is a happy number.

It is an a-pointer prime, because the next prime (426221041) can be obtained adding 426221021 to its sum of digits (20).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 323604121 + 102616900 = 17989^2 + 10130^2 .

It is a cyclic number.

It is not a de Polignac number, because 426221021 - 2¹⁸ = 425958877 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 426220984 and 426221002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (426221011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 213110510 + 213110511.

It is an arithmetic number, because the mean of its divisors is an integer number (213110511).

Almost surely, 2^426221021 is an apocalyptic number.

It is an amenable number.

426221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

426221021 is an equidigital number, since it uses as much as digits as its factorization.

426221021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 426221021 is about 20645.1209974657. The cubic root of 426221021 is about 752.5666264043.

Adding to 426221021 its reverse (120122624), we get a palindrome (546343645).

The spelling of 426221021 in words is "four hundred twenty-six million, two hundred twenty-one thousand, twenty-one".