666668347 has 2 divisors, whose sum is σ = 666668348. Its totient is φ = 666668346.

The previous prime is 666668309. The next prime is 666668357. The reversal of 666668347 is 743866666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666668347 - 2²⁷ = 532450619 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666668294 and 666668303.

It is not a weakly prime, because it can be changed into another prime (666668357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333334173 + 333334174.

It is an arithmetic number, because the mean of its divisors is an integer number (333334174).

Almost surely, 2^666668347 is an apocalyptic number.

666668347 is a deficient number, since it is larger than the sum of its proper divisors (1).

666668347 is an equidigital number, since it uses as much as digits as its factorization.

666668347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 52.

The square root of 666668347 is about 25819.9215142107. The cubic root of 666668347 is about 873.5811986889.

The spelling of 666668347 in words is "six hundred sixty-six million, six hundred sixty-eight thousand, three hundred forty-seven".