306666 has 24 divisors (see below), whose sum is σ = 690144. Its totient is φ = 102060.

The previous prime is 306661. The next prime is 306689. The reversal of 306666 is 666603.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

306666 is a modest number, since divided by 666 gives 306 as remainder.

It is not an unprimeable number, because it can be changed into a prime (306661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 171 + ... + 801.

It is an arithmetic number, because the mean of its divisors is an integer number (28756).

2³⁰⁶⁶⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 306666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345072).

306666 is an abundant number, since it is smaller than the sum of its proper divisors (383478).

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

306666 is an equidigital number, since it uses as much as digits as its factorization.

306666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648 (or 636 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 306666 is about 553.7743222649. The cubic root of 306666 is about 67.4354939303.

The spelling of 306666 in words is "three hundred six thousand, six hundred sixty-six".