It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a d-powerful number, because it can be written as 44 + 213 + 215 + 45 + 0 .
It is a nialpdrome in base 4 and base 16.
It is a zygodrome in base 4.
It is a congruent number.
It is an unprimeable number.
242240 is an apocalyptic number.
42240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 42240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73584).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
42240 is a wasteful number, since it uses less digits than its factorization.
42240 is an evil number, because the sum of its binary digits is even.
The square root of 42240 is about 205.5237212586. The cubic root of 42240 is about 34.8263507647.
Adding to 42240 its reverse (4224), we get a palindrome (46464).
The spelling of 42240 in words is "forty-two thousand, two hundred forty", and thus it is an iban number.