666636 has 24 divisors (see below), whose sum is σ = 1578864. Its totient is φ = 218880.

The previous prime is 666607. The next prime is 666637. The reversal of 666636 is 636666.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 666597 and 666606.

It is not an unprimeable number, because it can be changed into a prime (666637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 496 + ... + 1256.

It is an arithmetic number, because the mean of its divisors is an integer number (65786).

2⁶⁶⁶⁶³⁶ is an apocalyptic number.

It is an amenable number.

666636 is an abundant number, since it is smaller than the sum of its proper divisors (912228).

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

666636 is a wasteful number, since it uses less digits than its factorization.

666636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 841 (or 839 counting only the distinct ones).

The product of its digits is 23328, while the sum is 33.

The square root of 666636 is about 816.4778012904. The cubic root of 666636 is about 87.3567069630.

The spelling of 666636 in words is "six hundred sixty-six thousand, six hundred thirty-six".