666973 has 4 divisors (see below), whose sum is σ = 682528. Its totient is φ = 651420.

The previous prime is 666959. The next prime is 666979. The reversal of 666973 is 379666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 666973 - 2⁹ = 666461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7713 + ... + 7798.

It is an arithmetic number, because the mean of its divisors is an integer number (170632).

2⁶⁶⁶⁹⁷³ is an apocalyptic number.

It is an amenable number.

666973 is a deficient number, since it is larger than the sum of its proper divisors (15555).

666973 is a wasteful number, since it uses less digits than its factorization.

666973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15554.

The product of its digits is 40824, while the sum is 37.

The square root of 666973 is about 816.6841494727. The cubic root of 666973 is about 87.3714247655.

The spelling of 666973 in words is "six hundred sixty-six thousand, nine hundred seventy-three".