66679 has 4 divisors (see below), whose sum is σ = 67320. Its totient is φ = 66040.

The previous prime is 66653. The next prime is 66683. The reversal of 66679 is 97666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 66679 - 2¹⁵ = 33911 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124 + ... + 385.

It is an arithmetic number, because the mean of its divisors is an integer number (16830).

2⁶⁶⁶⁷⁹ is an apocalyptic number.

66679 is a deficient number, since it is larger than the sum of its proper divisors (641).

66679 is a wasteful number, since it uses less digits than its factorization.

66679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640.

The product of its digits is 13608, while the sum is 34.

The square root of 66679 is about 258.2227720400. Note that the first 3 decimals coincide. The cubic root of 66679 is about 40.5505136105.

The spelling of 66679 in words is "sixty-six thousand, six hundred seventy-nine".