206664666 has 16 divisors (see below), whose sum is σ = 445124064. Its totient is φ = 63589104.

The previous prime is 206664613. The next prime is 206664677. The reversal of 206664666 is 666466602.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1324696 + ... + 1324851.

It is an arithmetic number, because the mean of its divisors is an integer number (27820254).

Almost surely, 2^206664666 is an apocalyptic number.

206664666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

206664666 is an abundant number, since it is smaller than the sum of its proper divisors (238459398).

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

206664666 is a wasteful number, since it uses less digits than its factorization.

206664666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2649565.

The product of its (nonzero) digits is 373248, while the sum is 42.

The square root of 206664666 is about 14375.8361843755. The cubic root of 206664666 is about 591.2285670290.

The spelling of 206664666 in words is "two hundred six million, six hundred sixty-four thousand, six hundred sixty-six".