66656593 has 2 divisors, whose sum is σ = 66656594. Its totient is φ = 66656592.

The previous prime is 66656581. The next prime is 66656651. The reversal of 66656593 is 39565666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57274624 + 9381969 = 7568^2 + 3063^2 .

It is a cyclic number.

It is not a de Polignac number, because 66656593 - 2²¹ = 64559441 is a prime.

It is not a weakly prime, because it can be changed into another prime (66656533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33328296 + 33328297.

It is an arithmetic number, because the mean of its divisors is an integer number (33328297).

Almost surely, 2^66656593 is an apocalyptic number.

It is an amenable number.

66656593 is a deficient number, since it is larger than the sum of its proper divisors (1).

66656593 is an equidigital number, since it uses as much as digits as its factorization.

66656593 is an evil number, because the sum of its binary digits is even.

The product of its digits is 874800, while the sum is 46.

The square root of 66656593 is about 8164.3489023926. The cubic root of 66656593 is about 405.4597086509.

The spelling of 66656593 in words is "sixty-six million, six hundred fifty-six thousand, five hundred ninety-three".