666010001 has 2 divisors, whose sum is σ = 666010002. Its totient is φ = 666010000.

The previous prime is 666009991. The next prime is 666010043. The reversal of 666010001 is 100010666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 625050001 + 40960000 = 25001^2 + 6400^2 .

It is a cyclic number.

It is not a de Polignac number, because 666010001 - 2¹⁴ = 665993617 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666010061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333005000 + 333005001.

It is an arithmetic number, because the mean of its divisors is an integer number (333005001).

Almost surely, 2^666010001 is an apocalyptic number.

It is an amenable number.

666010001 is a deficient number, since it is larger than the sum of its proper divisors (1).

666010001 is an equidigital number, since it uses as much as digits as its factorization.

666010001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 666010001 is about 25807.1695658396. The cubic root of 666010001 is about 873.2935453615.

Adding to 666010001 its reverse (100010666), we get a palindrome (766020667).

It can be divided in two parts, 6660 and 10001, that added together give a palindrome (16661).

The spelling of 666010001 in words is "six hundred sixty-six million, ten thousand, one".