421410221 has 2 divisors, whose sum is σ = 421410222. Its totient is φ = 421410220.

The previous prime is 421410217. The next prime is 421410233. The reversal of 421410221 is 122014124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 302272996 + 119137225 = 17386^2 + 10915^2 .

It is a cyclic number.

It is not a de Polignac number, because 421410221 - 2² = 421410217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421410221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421410421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210705110 + 210705111.

It is an arithmetic number, because the mean of its divisors is an integer number (210705111).

Almost surely, 2^421410221 is an apocalyptic number.

It is an amenable number.

421410221 is a deficient number, since it is larger than the sum of its proper divisors (1).

421410221 is an equidigital number, since it uses as much as digits as its factorization.

421410221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 421410221 is about 20528.2785688425. The cubic root of 421410221 is about 749.7244742005.

Adding to 421410221 its reverse (122014124), we get a palindrome (543424345).

The spelling of 421410221 in words is "four hundred twenty-one million, four hundred ten thousand, two hundred twenty-one".