666658189 has 2 divisors, whose sum is σ = 666658190. Its totient is φ = 666658188.

The previous prime is 666658133. The next prime is 666658211. The reversal of 666658189 is 981856666.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 597069225 + 69588964 = 24435^2 + 8342^2 .

It is a cyclic number.

It is not a de Polignac number, because 666658189 - 2¹⁷ = 666527117 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666658129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333329094 + 333329095.

It is an arithmetic number, because the mean of its divisors is an integer number (333329095).

Almost surely, 2^666658189 is an apocalyptic number.

It is an amenable number.

666658189 is a deficient number, since it is larger than the sum of its proper divisors (1).

666658189 is an equidigital number, since it uses as much as digits as its factorization.

666658189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3732480, while the sum is 55.

The square root of 666658189 is about 25819.7248048851. The cubic root of 666658189 is about 873.5767617586.

The spelling of 666658189 in words is "six hundred sixty-six million, six hundred fifty-eight thousand, one hundred eighty-nine".