667006709 has 2 divisors, whose sum is σ = 667006710. Its totient is φ = 667006708.

The previous prime is 667006687. The next prime is 667006759. The reversal of 667006709 is 907600766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 621106084 + 45900625 = 24922^2 + 6775^2 .

It is a cyclic number.

It is not a de Polignac number, because 667006709 - 2⁸ = 667006453 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 (667006759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333503354 + 333503355.

It is an arithmetic number, because the mean of its divisors is an integer number (333503355).

Almost surely, 2^667006709 is an apocalyptic number.

It is an amenable number.

667006709 is a deficient number, since it is larger than the sum of its proper divisors (1).

667006709 is an equidigital number, since it uses as much as digits as its factorization.

667006709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 95256, while the sum is 41.

The square root of 667006709 is about 25826.4730267220. The cubic root of 667006709 is about 873.7289666605.

The spelling of 667006709 in words is "six hundred sixty-seven million, six thousand, seven hundred nine".