667216217509 has 2 divisors, whose sum is σ = 667216217510. Its totient is φ = 667216217508.

The previous prime is 667216217501. The next prime is 667216217531. The reversal of 667216217509 is 905712612766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653061166884 + 14155050625 = 808122^2 + 118975^2 .

It is a cyclic number.

It is not a de Polignac number, because 667216217509 - 2³ = 667216217501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667216217501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333608108754 + 333608108755.

It is an arithmetic number, because the mean of its divisors is an integer number (333608108755).

Almost surely, 2^667216217509 is an apocalyptic number.

It is an amenable number.

667216217509 is a deficient number, since it is larger than the sum of its proper divisors (1).

667216217509 is an equidigital number, since it uses as much as digits as its factorization.

667216217509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1905120, while the sum is 52.

The spelling of 667216217509 in words is "six hundred sixty-seven billion, two hundred sixteen million, two hundred seventeen thousand, five hundred nine".