42240 has 72 divisors (see below), whose sum is σ = 147168. Its totient is φ = 10240.

The previous prime is 42239. The next prime is 42257. The reversal of 42240 is 4224.

It is a hoax number, since the sum of its digits (12) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (12).

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.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3835 + ... + 3845.

It is an arithmetic number, because the mean of its divisors is an integer number (2044).

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).

42240 is an abundant number, since it is smaller than the sum of its proper divisors (104928).

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 sum of its prime factors is 35 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 12.

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).

It can be divided in two parts, 42 and 240, that added together give a palindrome (282).

The spelling of 42240 in words is "forty-two thousand, two hundred forty", and thus it is an iban number.