1665636 has 48 divisors (see below), whose sum is σ = 4515840. Its totient is φ = 468000.

The previous prime is 1665623. The next prime is 1665647. The reversal of 1665636 is 6365661.

It is a junction number, because it is equal to n+sod(n) for n = 1665597 and 1665606.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6511 + ... + 6761.

It is an arithmetic number, because the mean of its divisors is an integer number (94080).

2^1665636 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 1665636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2257920).

1665636 is an abundant number, since it is smaller than the sum of its proper divisors (2850204).

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

1665636 is a wasteful number, since it uses less digits than its factorization.

1665636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 342 counting only the distinct ones).

The product of its digits is 19440, while the sum is 33.

The square root of 1665636 is about 1290.5952115206. The cubic root of 1665636 is about 118.5386653010.

The spelling of 1665636 in words is "one million, six hundred sixty-five thousand, six hundred thirty-six".