666768043801 has 2 divisors, whose sum is σ = 666768043802. Its totient is φ = 666768043800.

The previous prime is 666768043769. The next prime is 666768043847. The reversal of 666768043801 is 108340867666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 382226880025 + 284541163776 = 618245^2 + 533424^2 .

It is a cyclic number.

It is not a de Polignac number, because 666768043801 - 2⁵ = 666768043769 is a prime.

It is not a weakly prime, because it can be changed into another prime (666768043001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333384021900 + 333384021901.

It is an arithmetic number, because the mean of its divisors is an integer number (333384021901).

Almost surely, 2^666768043801 is an apocalyptic number.

It is an amenable number.

666768043801 is a deficient number, since it is larger than the sum of its proper divisors (1).

666768043801 is an equidigital number, since it uses as much as digits as its factorization.

666768043801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6967296, while the sum is 55.

The spelling of 666768043801 in words is "six hundred sixty-six billion, seven hundred sixty-eight million, forty-three thousand, eight hundred one".