666654169 has 2 divisors, whose sum is σ = 666654170. Its totient is φ = 666654168.

The previous prime is 666654151. The next prime is 666654173. The reversal of 666654169 is 961456666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 441504144 + 225150025 = 21012^2 + 15005^2 .

It is a cyclic number.

It is not a de Polignac number, because 666654169 - 2¹³ = 666645977 is a prime.

It is a super-2 number, since 2×666654169² = 888855562090161122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666654119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333327084 + 333327085.

It is an arithmetic number, because the mean of its divisors is an integer number (333327085).

Almost surely, 2^666654169 is an apocalyptic number.

It is an amenable number.

666654169 is a deficient number, since it is larger than the sum of its proper divisors (1).

666654169 is an equidigital number, since it uses as much as digits as its factorization.

666654169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1399680, while the sum is 49.

The square root of 666654169 is about 25819.6469573075. The cubic root of 666654169 is about 873.5750058435.

The spelling of 666654169 in words is "six hundred sixty-six million, six hundred fifty-four thousand, one hundred sixty-nine".