666787559 has 2 divisors, whose sum is σ = 666787560. Its totient is φ = 666787558.

The previous prime is 666787531. The next prime is 666787567. The reversal of 666787559 is 955787666.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666787559 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 666787498 and 666787507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666787519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333393779 + 333393780.

It is an arithmetic number, because the mean of its divisors is an integer number (333393780).

Almost surely, 2^666787559 is an apocalyptic number.

666787559 is a deficient number, since it is larger than the sum of its proper divisors (1).

666787559 is an equidigital number, since it uses as much as digits as its factorization.

666787559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19051200, while the sum is 59.

The square root of 666787559 is about 25822.2299385626. The cubic root of 666787559 is about 873.6332661352.

The spelling of 666787559 in words is "six hundred sixty-six million, seven hundred eighty-seven thousand, five hundred fifty-nine".