666986973 has 8 divisors (see below), whose sum is σ = 889446336. Its totient is φ = 444592800.

The previous prime is 666986953. The next prime is 666986977. The reversal of 666986973 is 379689666.

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

It is not a de Polignac number, because 666986973 - 2²⁴ = 650209757 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666986977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17728 + ... + 40598.

It is an arithmetic number, because the mean of its divisors is an integer number (111180792).

Almost surely, 2^666986973 is an apocalyptic number.

It is an amenable number.

666986973 is a deficient number, since it is larger than the sum of its proper divisors (222459363).

666986973 is a wasteful number, since it uses less digits than its factorization.

666986973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32595.

The product of its digits is 17635968, while the sum is 60.

The square root of 666986973 is about 25826.0909353313. The cubic root of 666986973 is about 873.7203490135.

The spelling of 666986973 in words is "six hundred sixty-six million, nine hundred eighty-six thousand, nine hundred seventy-three".