666648001 has 2 divisors, whose sum is σ = 666648002. Its totient is φ = 666648000.

The previous prime is 666647999. The next prime is 666648007. The reversal of 666648001 is 100846666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 416976400 + 249671601 = 20420^2 + 15801^2 .

It is a cyclic number.

It is not a de Polignac number, because 666648001 - 2¹ = 666647999 is a prime.

Together with 666647999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (666648007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333324000 + 333324001.

It is an arithmetic number, because the mean of its divisors is an integer number (333324001).

Almost surely, 2^666648001 is an apocalyptic number.

It is an amenable number.

666648001 is a deficient number, since it is larger than the sum of its proper divisors (1).

666648001 is an equidigital number, since it uses as much as digits as its factorization.

666648001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 666648001 is about 25819.5275131053. The cubic root of 666648001 is about 873.5723116793.

The spelling of 666648001 in words is "six hundred sixty-six million, six hundred forty-eight thousand, one".