421845 has 8 divisors (see below), whose sum is σ = 674976. Its totient is φ = 224976.

The previous prime is 421831. The next prime is 421847. The reversal of 421845 is 548124.

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

It is not a de Polignac number, because 421845 - 2⁷ = 421717 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 421845.

It is not an unprimeable number, because it can be changed into a prime (421847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14047 + ... + 14076.

It is an arithmetic number, because the mean of its divisors is an integer number (84372).

2⁴²¹⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

421845 is a deficient number, since it is larger than the sum of its proper divisors (253131).

421845 is a wasteful number, since it uses less digits than its factorization.

421845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28131.

The product of its digits is 1280, while the sum is 24.

The square root of 421845 is about 649.4959584170. The cubic root of 421845 is about 74.9982221801.

Subtracting from 421845 its sum of digits (24), we obtain a triangular number (421821 = T₉₁₈).

Adding to 421845 its reverse (548124), we get a palindrome (969969).

The spelling of 421845 in words is "four hundred twenty-one thousand, eight hundred forty-five".