421205 has 8 divisors (see below), whose sum is σ = 514104. Its totient is φ = 331200.

The previous prime is 421189. The next prime is 421207. The reversal of 421205 is 502124.

It can be written as a sum of positive squares in 4 ways, for example, as 4 + 421201 = 2^2 + 649^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 421205 - 2⁴ = 421189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 421205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421207) 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 7 ways as a sum of consecutive naturals, for example, 386 + ... + 995.

It is an arithmetic number, because the mean of its divisors is an integer number (64263).

2⁴²¹²⁰⁵ is an apocalyptic number.

It is an amenable number.

421205 is a deficient number, since it is larger than the sum of its proper divisors (92899).

421205 is a wasteful number, since it uses less digits than its factorization.

421205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1447.

The product of its (nonzero) digits is 80, while the sum is 14.

The square root of 421205 is about 649.0030816568. The cubic root of 421205 is about 74.9602752593.

Adding to 421205 its reverse (502124), we get a palindrome (923329).

It can be divided in two parts, 421 and 205, that added together give a palindrome (626).

The spelling of 421205 in words is "four hundred twenty-one thousand, two hundred five".