666907 has 4 divisors (see below), whose sum is σ = 669816. Its totient is φ = 664000.

The previous prime is 666901. The next prime is 666929. The reversal of 666907 is 709666.

666907 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 709666 = 2 ⋅354833.

It is a cyclic number.

It is not a de Polignac number, because 666907 - 2¹⁹ = 142619 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666901) 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, 1078 + ... + 1579.

It is an arithmetic number, because the mean of its divisors is an integer number (167454).

2⁶⁶⁶⁹⁰⁷ is an apocalyptic number.

666907 is a deficient number, since it is larger than the sum of its proper divisors (2909).

666907 is a wasteful number, since it uses less digits than its factorization.

666907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2908.

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

The square root of 666907 is about 816.6437411748. The cubic root of 666907 is about 87.3685427377.

The spelling of 666907 in words is "six hundred sixty-six thousand, nine hundred seven".