666187607 has 2 divisors, whose sum is σ = 666187608. Its totient is φ = 666187606.

The previous prime is 666187567. The next prime is 666187609. The reversal of 666187607 is 706781666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666187607 - 2¹⁰ = 666186583 is a prime.

Together with 666187609, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666187609) 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, 333093803 + 333093804.

It is an arithmetic number, because the mean of its divisors is an integer number (333093804).

Almost surely, 2^666187607 is an apocalyptic number.

666187607 is a deficient number, since it is larger than the sum of its proper divisors (1).

666187607 is an equidigital number, since it uses as much as digits as its factorization.

666187607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 47.

The square root of 666187607 is about 25810.6103569830. The cubic root of 666187607 is about 873.3711660119.

The spelling of 666187607 in words is "six hundred sixty-six million, one hundred eighty-seven thousand, six hundred seven".