420221 has 2 divisors, whose sum is σ = 420222. Its totient is φ = 420220.

The previous prime is 420193. The next prime is 420241. The reversal of 420221 is 122024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 264196 + 156025 = 514^2 + 395^2 .

It is a cyclic number.

It is not a de Polignac number, because 420221 - 2¹⁸ = 158077 is a prime.

It is a plaindrome in base 11.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210110 + 210111.

It is an arithmetic number, because the mean of its divisors is an integer number (210111).

2⁴²⁰²²¹ is an apocalyptic number.

It is an amenable number.

420221 is a deficient number, since it is larger than the sum of its proper divisors (1).

420221 is an equidigital number, since it uses as much as digits as its factorization.

420221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 11.

The square root of 420221 is about 648.2445526188. The cubic root of 420221 is about 74.9018568134.

Adding to 420221 its reverse (122024), we get a palindrome (542245).

The spelling of 420221 in words is "four hundred twenty thousand, two hundred twenty-one", and thus it is an iban number.