665542201 has 2 divisors, whose sum is σ = 665542202. Its totient is φ = 665542200.

The previous prime is 665542181. The next prime is 665542211. The reversal of 665542201 is 102245566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 640140601 + 25401600 = 25301^2 + 5040^2 .

It is a cyclic number.

It is not a de Polignac number, because 665542201 - 2⁹ = 665541689 is a prime.

It is not a weakly prime, because it can be changed into another prime (665542211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332771100 + 332771101.

It is an arithmetic number, because the mean of its divisors is an integer number (332771101).

Almost surely, 2^665542201 is an apocalyptic number.

It is an amenable number.

665542201 is a deficient number, since it is larger than the sum of its proper divisors (1).

665542201 is an equidigital number, since it uses as much as digits as its factorization.

665542201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 665542201 is about 25798.1046009198. The cubic root of 665542201 is about 873.0890327136.

Adding to 665542201 its reverse (102245566), we get a palindrome (767787767).

The spelling of 665542201 in words is "six hundred sixty-five million, five hundred forty-two thousand, two hundred one".