421784 has 16 divisors (see below), whose sum is σ = 862920. Its totient is φ = 191680.

The previous prime is 421783. The next prime is 421801. The reversal of 421784 is 487124.

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 421784.

It is not an unprimeable number, because it can be changed into a prime (421783) 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, 2309 + ... + 2484.

2⁴²¹⁷⁸⁴ is an apocalyptic number.

421784 is a gapful number since it is divisible by the number (44) formed by its first and last digit.

It is an amenable number.

421784 is an abundant number, since it is smaller than the sum of its proper divisors (441136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

421784 is a wasteful number, since it uses less digits than its factorization.

421784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4810 (or 4806 counting only the distinct ones).

The product of its digits is 1792, while the sum is 26.

The square root of 421784 is about 649.4489972276. The cubic root of 421784 is about 74.9946070196.

The spelling of 421784 in words is "four hundred twenty-one thousand, seven hundred eighty-four".