66668 has 12 divisors (see below), whose sum is σ = 133392. Its totient is φ = 28560.

The previous prime is 66653. The next prime is 66683. The reversal of 66668 is 86666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66653) and next prime (66683).

66668 is an admirable number.

It is a plaindrome in base 10.

It is an unprimeable number.

66668 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1163 + ... + 1218.

It is an arithmetic number, because the mean of its divisors is an integer number (11116).

2⁶⁶⁶⁶⁸ is an apocalyptic number.

It is an amenable number.

66668 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66696).

66668 is a wasteful number, since it uses less digits than its factorization.

66668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2392 (or 2390 counting only the distinct ones).

The product of its digits is 10368, while the sum is 32.

The square root of 66668 is about 258.2014717231. The cubic root of 66668 is about 40.5482836221.

The spelling of 66668 in words is "sixty-six thousand, six hundred sixty-eight".