666906 has 16 divisors (see below), whose sum is σ = 1366848. Its totient is φ = 216800.

The previous prime is 666901. The next prime is 666929. The reversal of 666906 is 609666.

It is a super-2 number, since 2×666906² = 889527225672, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1110 + ... + 1601.

It is an arithmetic number, because the mean of its divisors is an integer number (85428).

2⁶⁶⁶⁹⁰⁶ is an apocalyptic number.

666906 is an abundant number, since it is smaller than the sum of its proper divisors (699942).

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

666906 is a wasteful number, since it uses less digits than its factorization.

666906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2757.

The product of its (nonzero) digits is 11664, while the sum is 33.

The square root of 666906 is about 816.6431289125. The cubic root of 666906 is about 87.3684990691.

The spelling of 666906 in words is "six hundred sixty-six thousand, nine hundred six".