16665636 has 48 divisors (see below), whose sum is σ = 42787584. Its totient is φ = 5016576.

The previous prime is 16665629. The next prime is 16665637. The reversal of 16665636 is 63656661.

16665636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 16665594 and 16665603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16665637) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6196 + ... + 8468.

It is an arithmetic number, because the mean of its divisors is an integer number (891408).

Almost surely, 2^16665636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16665636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21393792).

16665636 is an abundant number, since it is smaller than the sum of its proper divisors (26121948).

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

16665636 is a wasteful number, since it uses less digits than its factorization.

16665636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2340 (or 2338 counting only the distinct ones).

The product of its digits is 116640, while the sum is 39.

The square root of 16665636 is about 4082.3566723156. The cubic root of 16665636 is about 255.4312119587.

Subtracting 16665636 from its reverse (63656661), we obtain a square (46991025 = 6855²).

The spelling of 16665636 in words is "sixteen million, six hundred sixty-five thousand, six hundred thirty-six".