It is a tau number, because it is divible by the number of its divisors (12).
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 421404.
421404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2421404 is an apocalyptic number.
It is an amenable number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
421404 is a wasteful number, since it uses less digits than its factorization.
421404 is an evil number, because the sum of its binary digits is even.
The square root of 421404 is about 649.1563756138. The cubic root of 421404 is about 74.9720784954.
Adding to 421404 its reverse (404124), we get a palindrome (825528).
The spelling of 421404 in words is "four hundred twenty-one thousand, four hundred four", and thus it is an iban number.