66205603 has 2 divisors, whose sum is σ = 66205604. Its totient is φ = 66205602.

The previous prime is 66205597. The next prime is 66205613. The reversal of 66205603 is 30650266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66205603 - 2⁹ = 66205091 is a prime.

It is equal to p_3907603 and since 66205603 and 3907603 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (66205613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33102801 + 33102802.

It is an arithmetic number, because the mean of its divisors is an integer number (33102802).

Almost surely, 2^66205603 is an apocalyptic number.

66205603 is a deficient number, since it is larger than the sum of its proper divisors (1).

66205603 is an equidigital number, since it uses as much as digits as its factorization.

66205603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 28.

The square root of 66205603 is about 8136.6825549483. The cubic root of 66205603 is about 404.5432090146.

Adding to 66205603 its reverse (30650266), we get a palindrome (96855869).

The spelling of 66205603 in words is "sixty-six million, two hundred five thousand, six hundred three".