16005440 has 56 divisors (see below), whose sum is σ = 41586912. Its totient is φ = 5818880.

The previous prime is 16005421. The next prime is 16005443. The reversal of 16005440 is 4450061.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16005443) 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, 1247 + ... + 5793.

Almost surely, 2^16005440 is an apocalyptic number.

16005440 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 16005440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20793456).

16005440 is an abundant number, since it is smaller than the sum of its proper divisors (25581472).

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

16005440 is a wasteful number, since it uses less digits than its factorization.

16005440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4575 (or 4565 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 16005440 is about 4000.6799422098. The cubic root of 16005440 is about 252.0127649535.

The spelling of 16005440 in words is "sixteen million, five thousand, four hundred forty".