16565640 has 256 divisors, whose sum is σ = 64350720. Its totient is φ = 3317760.

The previous prime is 16565639. The next prime is 16565651. The reversal of 16565640 is 4656561.

16565640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 404020 + ... + 404060.

It is an arithmetic number, because the mean of its divisors is an integer number (251370).

Almost surely, 2^16565640 is an apocalyptic number.

16565640 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 16565640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175360).

16565640 is an abundant number, since it is smaller than the sum of its proper divisors (47785080).

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

16565640 is a wasteful number, since it uses less digits than its factorization.

16565640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 16565640 is about 4070.0909080756. The cubic root of 16565640 is about 254.9193131877.

It can be divided in two parts, 16565 and 640, that added together give a triangular number (17205 = T₁₈₅).

The spelling of 16565640 in words is "sixteen million, five hundred sixty-five thousand, six hundred forty".