665110001 has 2 divisors, whose sum is σ = 665110002. Its totient is φ = 665110000.

The previous prime is 665109997. The next prime is 665110027. The reversal of 665110001 is 100011566.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 577200625 + 87909376 = 24025^2 + 9376^2 .

It is a cyclic number.

It is not a de Polignac number, because 665110001 - 2² = 665109997 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665110051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332555000 + 332555001.

It is an arithmetic number, because the mean of its divisors is an integer number (332555001).

Almost surely, 2^665110001 is an apocalyptic number.

It is an amenable number.

665110001 is a deficient number, since it is larger than the sum of its proper divisors (1).

665110001 is an equidigital number, since it uses as much as digits as its factorization.

665110001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 665110001 is about 25789.7266561707. The cubic root of 665110001 is about 872.8999984737.

Adding to 665110001 its reverse (100011566), we get a palindrome (765121567).

The spelling of 665110001 in words is "six hundred sixty-five million, one hundred ten thousand, one".