66916189 has 2 divisors, whose sum is σ = 66916190. Its totient is φ = 66916188.

The previous prime is 66916181. The next prime is 66916231. The reversal of 66916189 is 98161966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66504025 + 412164 = 8155^2 + 642^2 .

It is a cyclic number.

It is not a de Polignac number, because 66916189 - 2³ = 66916181 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 (66916181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33458094 + 33458095.

It is an arithmetic number, because the mean of its divisors is an integer number (33458095).

Almost surely, 2^66916189 is an apocalyptic number.

It is an amenable number.

66916189 is a deficient number, since it is larger than the sum of its proper divisors (1).

66916189 is an equidigital number, since it uses as much as digits as its factorization.

66916189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 46.

The square root of 66916189 is about 8180.2315981884. The cubic root of 66916189 is about 405.9853849479.

It can be divided in two parts, 6691 and 6189, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 66916189 in words is "sixty-six million, nine hundred sixteen thousand, one hundred eighty-nine".