666718 has 8 divisors (see below), whose sum is σ = 1077048. Its totient is φ = 307704.

The previous prime is 666707. The next prime is 666727. The reversal of 666718 is 817666.

666718 is nontrivially palindromic in base 15.

666718 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

666718 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, 12796 + ... + 12847.

It is an arithmetic number, because the mean of its divisors is an integer number (134631).

2⁶⁶⁶⁷¹⁸ is an apocalyptic number.

666718 is a deficient number, since it is larger than the sum of its proper divisors (410330).

666718 is a wasteful number, since it uses less digits than its factorization.

666718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25658.

The product of its digits is 12096, while the sum is 34.

The square root of 666718 is about 816.5280154410. The cubic root of 666718 is about 87.3602886059.

The spelling of 666718 in words is "six hundred sixty-six thousand, seven hundred eighteen".