42440 has 16 divisors (see below), whose sum is σ = 95580. Its totient is φ = 16960.

The previous prime is 42437. The next prime is 42443. The reversal of 42440 is 4424.

It is an interprime number because it is at equal distance from previous prime (42437) and next prime (42443).

It can be written as a sum of positive squares in 2 ways, for example, as 42436 + 4 = 206^2 + 2^2 .

It is not an unprimeable number, because it can be changed into a prime (42443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 491 + ... + 570.

2⁴²⁴⁴⁰ is an apocalyptic number.

42440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42440 is an abundant number, since it is smaller than the sum of its proper divisors (53140).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47790).

42440 is a wasteful number, since it uses less digits than its factorization.

42440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072 (or 1068 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 14.

The square root of 42440 is about 206.0097085091. The cubic root of 42440 is about 34.8812300719.

Adding to 42440 its reverse (4424), we get a palindrome (46864).

It can be divided in two parts, 424 and 40, that added together give a palindrome (464).

The spelling of 42440 in words is "forty-two thousand, four hundred forty", and thus it is an iban number.