66636601 has 2 divisors, whose sum is σ = 66636602. Its totient is φ = 66636600.

The previous prime is 66636569. The next prime is 66636631. The reversal of 66636601 is 10663666.

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., 66406201 + 230400 = 8149^2 + 480^2 .

It is a cyclic number.

It is not a de Polignac number, because 66636601 - 2⁵ = 66636569 is a prime.

It is not a weakly prime, because it can be changed into another prime (66636631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33318300 + 33318301.

It is an arithmetic number, because the mean of its divisors is an integer number (33318301).

Almost surely, 2^66636601 is an apocalyptic number.

It is an amenable number.

66636601 is a deficient number, since it is larger than the sum of its proper divisors (1).

66636601 is an equidigital number, since it uses as much as digits as its factorization.

66636601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 34.

The square root of 66636601 is about 8163.1244630962. The cubic root of 66636601 is about 405.4191687200.

The spelling of 66636601 in words is "sixty-six million, six hundred thirty-six thousand, six hundred one".