6666749 has 2 divisors, whose sum is σ = 6666750. Its totient is φ = 6666748.

The previous prime is 6666719. The next prime is 6666761. The reversal of 6666749 is 9476666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6666724 + 25 = 2582^2 + 5^2 .

It is a cyclic number.

It is not a de Polignac number, because 6666749 - 2¹⁶ = 6601213 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6666719) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333374 + 3333375.

It is an arithmetic number, because the mean of its divisors is an integer number (3333375).

Almost surely, 2^6666749 is an apocalyptic number.

It is an amenable number.

6666749 is a deficient number, since it is larger than the sum of its proper divisors (1).

6666749 is an equidigital number, since it uses as much as digits as its factorization.

6666749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 44.

The square root of 6666749 is about 2582.0048412038. The cubic root of 6666749 is about 188.2079805593.

The spelling of 6666749 in words is "six million, six hundred sixty-six thousand, seven hundred forty-nine".