66686 has 4 divisors (see below), whose sum is σ = 100032. Its totient is φ = 33342.

The previous prime is 66683. The next prime is 66697. The reversal of 66686 is 68666.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16670 + ... + 16673.

It is an arithmetic number, because the mean of its divisors is an integer number (25008).

2⁶⁶⁶⁸⁶ is an apocalyptic number.

66686 is a deficient number, since it is larger than the sum of its proper divisors (33346).

66686 is a wasteful number, since it uses less digits than its factorization.

66686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33345.

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

The square root of 66686 is about 258.2363258723. The cubic root of 66686 is about 40.5519325663.

The spelling of 66686 in words is "sixty-six thousand, six hundred eighty-six".