66865583 has 2 divisors, whose sum is σ = 66865584. Its totient is φ = 66865582.

The previous prime is 66865553. The next prime is 66865597. The reversal of 66865583 is 38556866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66865583 - 2¹⁰ = 66864559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66865553) 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, 33432791 + 33432792.

It is an arithmetic number, because the mean of its divisors is an integer number (33432792).

Almost surely, 2^66865583 is an apocalyptic number.

66865583 is a deficient number, since it is larger than the sum of its proper divisors (1).

66865583 is an equidigital number, since it uses as much as digits as its factorization.

66865583 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1036800, while the sum is 47.

The square root of 66865583 is about 8177.1378244469. The cubic root of 66865583 is about 405.8830157103.

The spelling of 66865583 in words is "sixty-six million, eight hundred sixty-five thousand, five hundred eighty-three".