666993 has 8 divisors (see below), whose sum is σ = 894208. Its totient is φ = 442224.

The previous prime is 666989. The next prime is 667013. The reversal of 666993 is 399666.

666993 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 not a de Polignac number, because 666993 - 2² = 666989 is a prime.

It is a Duffinian number.

666993 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171 + ... + 1167.

It is an arithmetic number, because the mean of its divisors is an integer number (111776).

2⁶⁶⁶⁹⁹³ is an apocalyptic number.

It is an amenable number.

666993 is a deficient number, since it is larger than the sum of its proper divisors (227215).

666993 is a wasteful number, since it uses less digits than its factorization.

666993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1223.

The product of its digits is 52488, while the sum is 39.

The square root of 666993 is about 816.6963940168. The cubic root of 666993 is about 87.3722980697.

The spelling of 666993 in words is "six hundred sixty-six thousand, nine hundred ninety-three".