666043636 has 12 divisors (see below), whose sum is σ = 1165806180. Its totient is φ = 332956160.

The previous prime is 666043621. The next prime is 666043681. The reversal of 666043636 is 636340666.

666043636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 404251236 + 261792400 = 20106^2 + 16180^2 .

It is a super-2 number, since 2×666043636² = 887228250112200992, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11796 + ... + 38356.

It is an arithmetic number, because the mean of its divisors is an integer number (97150515).

Almost surely, 2^666043636 is an apocalyptic number.

It is an amenable number.

666043636 is a deficient number, since it is larger than the sum of its proper divisors (499762544).

666043636 is a wasteful number, since it uses less digits than its factorization.

666043636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32834 (or 32832 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 40.

The square root of 666043636 is about 25807.8212176077. The cubic root of 666043636 is about 873.3082462088.

The spelling of 666043636 in words is "six hundred sixty-six million, forty-three thousand, six hundred thirty-six".