16440 has 32 divisors (see below), whose sum is σ = 49680. Its totient is φ = 4352.

The previous prime is 16433. The next prime is 16447. The reversal of 16440 is 4461.

It is an interprime number because it is at equal distance from previous prime (16433) and next prime (16447).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52 + ... + 188.

16440 is a gapful number since it is divisible by the number (10) 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 16440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24840).

16440 is an abundant number, since it is smaller than the sum of its proper divisors (33240).

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

16440 is a wasteful number, since it uses less digits than its factorization.

16440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 16440 is about 128.2185633986. The cubic root of 16440 is about 25.4273209237.

It can be divided in two parts, 1 and 6440, that added together give a triangular number (6441 = T₁₁₃).

The spelling of 16440 in words is "sixteen thousand, four hundred forty".