421023221 has 2 divisors, whose sum is σ = 421023222. Its totient is φ = 421023220.

The previous prime is 421023217. The next prime is 421023263. The reversal of 421023221 is 122320124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 219780625 + 201242596 = 14825^2 + 14186^2 .

It is a cyclic number.

It is not a de Polignac number, because 421023221 - 2² = 421023217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 421023221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421023271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210511610 + 210511611.

It is an arithmetic number, because the mean of its divisors is an integer number (210511611).

Almost surely, 2^421023221 is an apocalyptic number.

It is an amenable number.

421023221 is a deficient number, since it is larger than the sum of its proper divisors (1).

421023221 is an equidigital number, since it uses as much as digits as its factorization.

421023221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 421023221 is about 20518.8503820268. The cubic root of 421023221 is about 749.4949019851.

Adding to 421023221 its reverse (122320124), we get a palindrome (543343345).

The spelling of 421023221 in words is "four hundred twenty-one million, twenty-three thousand, two hundred twenty-one".