66616189 has 2 divisors, whose sum is σ = 66616190. Its totient is φ = 66616188.

The previous prime is 66616171. The next prime is 66616201. The reversal of 66616189 is 98161666.

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., 63920025 + 2696164 = 7995^2 + 1642^2 .

It is a cyclic number.

It is not a de Polignac number, because 66616189 - 2¹³ = 66607997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66616129) 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, 33308094 + 33308095.

It is an arithmetic number, because the mean of its divisors is an integer number (33308095).

Almost surely, 2^66616189 is an apocalyptic number.

It is an amenable number.

66616189 is a deficient number, since it is larger than the sum of its proper divisors (1).

66616189 is an equidigital number, since it uses as much as digits as its factorization.

66616189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 43.

The square root of 66616189 is about 8161.8741107665. The cubic root of 66616189 is about 405.3777687433.

The spelling of 66616189 in words is "sixty-six million, six hundred sixteen thousand, one hundred eighty-nine".