666774247 has 2 divisors, whose sum is σ = 666774248. Its totient is φ = 666774246.

The previous prime is 666774203. The next prime is 666774253. The reversal of 666774247 is 742477666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666774247 - 2¹¹ = 666772199 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 666774247.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666774047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333387123 + 333387124.

It is an arithmetic number, because the mean of its divisors is an integer number (333387124).

Almost surely, 2^666774247 is an apocalyptic number.

666774247 is a deficient number, since it is larger than the sum of its proper divisors (1).

666774247 is an equidigital number, since it uses as much as digits as its factorization.

666774247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2370816, while the sum is 49.

The square root of 666774247 is about 25821.9721748746. The cubic root of 666774247 is about 873.6274522477.

The spelling of 666774247 in words is "six hundred sixty-six million, seven hundred seventy-four thousand, two hundred forty-seven".