421221 has 4 divisors (see below), whose sum is σ = 561632. Its totient is φ = 280812.

The previous prime is 421207. The next prime is 421241. The reversal of 421221 is 122124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 421221 - 2⁵ = 421189 is a prime.

It is a D-number.

It is a Duffinian number.

421221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 421197 and 421206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70201 + ... + 70206.

It is an arithmetic number, because the mean of its divisors is an integer number (140408).

2⁴²¹²²¹ is an apocalyptic number.

It is an amenable number.

421221 is a deficient number, since it is larger than the sum of its proper divisors (140411).

421221 is a wasteful number, since it uses less digits than its factorization.

421221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140410.

The product of its digits is 32, while the sum is 12.

The square root of 421221 is about 649.0154081376. The cubic root of 421221 is about 74.9612244006.

Adding to 421221 its reverse (122124), we get a palindrome (543345).

The spelling of 421221 in words is "four hundred twenty-one thousand, two hundred twenty-one", and thus it is an iban number.