66908189 has 2 divisors, whose sum is σ = 66908190. Its totient is φ = 66908188.

The previous prime is 66908167. The next prime is 66908201. The reversal of 66908189 is 98180966.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 36844900 + 30063289 = 6070^2 + 5483^2 .

It is a cyclic number.

It is not a de Polignac number, because 66908189 - 2⁸ = 66907933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66908089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33454094 + 33454095.

It is an arithmetic number, because the mean of its divisors is an integer number (33454095).

Almost surely, 2^66908189 is an apocalyptic number.

It is an amenable number.

66908189 is a deficient number, since it is larger than the sum of its proper divisors (1).

66908189 is an equidigital number, since it uses as much as digits as its factorization.

66908189 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 66908189 is about 8179.7425998622. The cubic root of 66908189 is about 405.9692054426.

The spelling of 66908189 in words is "sixty-six million, nine hundred eight thousand, one hundred eighty-nine".