40440 has 32 divisors (see below), whose sum is σ = 121680. Its totient is φ = 10752.

The previous prime is 40433. The next prime is 40459. The reversal of 40440 is 4404.

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 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, 49 + ... + 288.

2⁴⁰⁴⁴⁰ is an apocalyptic number.

40440 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 40440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60840).

40440 is an abundant number, since it is smaller than the sum of its proper divisors (81240).

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

40440 is a wasteful number, since it uses less digits than its factorization.

40440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 347 counting only the distinct ones).

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

The square root of 40440 is about 201.0969915240. The cubic root of 40440 is about 34.3244601655.

Adding to 40440 its product of nonzero digits (64), we get a palindrome (40504).

Adding to 40440 its reverse (4404), we get a palindrome (44844).

It can be divided in two parts, 404 and 40, that added together give a palindrome (444).

The spelling of 40440 in words is "forty thousand, four hundred forty", and thus it is an iban number.