8440 has 16 divisors (see below), whose sum is σ = 19080. Its totient is φ = 3360.

The previous prime is 8431. The next prime is 8443. The reversal of 8440 is 448.

8440 = 15² + 16² + ... + 30².

It is a plaindrome in base 15.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66 + ... + 145.

2⁸⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

8440 is an abundant number, since it is smaller than the sum of its proper divisors (10640).

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 (9540).

8440 is a wasteful number, since it uses less digits than its factorization.

8440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 8440 is about 91.8694726228. The cubic root of 8440 is about 20.3601426056.

Adding to 8440 its reverse (448), we get a palindrome (8888).

The spelling of 8440 in words is "eight thousand, four hundred forty".