636666 has 16 divisors (see below), whose sum is σ = 1317600. Its totient is φ = 204848.

The previous prime is 636653. The next prime is 636673. The reversal of 636666 is 666636.

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

636666 is a modest number, since divided by 666 gives 636 as remainder.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1656 + ... + 2003.

It is an arithmetic number, because the mean of its divisors is an integer number (82350).

2⁶³⁶⁶⁶⁶ is an apocalyptic number.

636666 is an abundant number, since it is smaller than the sum of its proper divisors (680934).

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

636666 is a wasteful number, since it uses less digits than its factorization.

636666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3693.

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

The square root of 636666 is about 797.9135291496. The cubic root of 636666 is about 86.0274835542.

The spelling of 636666 in words is "six hundred thirty-six thousand, six hundred sixty-six".