668536801 has 2 divisors, whose sum is σ = 668536802. Its totient is φ = 668536800.

The previous prime is 668536783. The next prime is 668536853. The reversal of 668536801 is 108635866.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 482241600 + 186295201 = 21960^2 + 13649^2 .

It is a cyclic number.

It is not a de Polignac number, because 668536801 - 2⁵ = 668536769 is a prime.

It is not a weakly prime, because it can be changed into another prime (668536861) 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, 334268400 + 334268401.

It is an arithmetic number, because the mean of its divisors is an integer number (334268401).

Almost surely, 2^668536801 is an apocalyptic number.

It is an amenable number.

668536801 is a deficient number, since it is larger than the sum of its proper divisors (1).

668536801 is an equidigital number, since it uses as much as digits as its factorization.

668536801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 43.

The square root of 668536801 is about 25856.0786083273. The cubic root of 668536801 is about 874.3965585188.

The spelling of 668536801 in words is "six hundred sixty-eight million, five hundred thirty-six thousand, eight hundred one".