666206679 has 8 divisors (see below), whose sum is σ = 890960512. Its totient is φ = 442795320.

The previous prime is 666206641. The next prime is 666206683. The reversal of 666206679 is 976602666.

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

It is not a de Polignac number, because 666206679 - 2⁷ = 666206551 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 (666206609) 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, 334459 + ... + 336444.

It is an arithmetic number, because the mean of its divisors is an integer number (111370064).

Almost surely, 2^666206679 is an apocalyptic number.

666206679 is a deficient number, since it is larger than the sum of its proper divisors (224753833).

666206679 is a wasteful number, since it uses less digits than its factorization.

666206679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671237.

The product of its (nonzero) digits is 979776, while the sum is 48.

The square root of 666206679 is about 25810.9798147997. The cubic root of 666206679 is about 873.3795003888.

The spelling of 666206679 in words is "six hundred sixty-six million, two hundred six thousand, six hundred seventy-nine".