666443513 has 2 divisors, whose sum is σ = 666443514. Its totient is φ = 666443512.

The previous prime is 666443507. The next prime is 666443543. The reversal of 666443513 is 315344666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 351487504 + 314956009 = 18748^2 + 17747^2 .

It is a cyclic number.

It is not a de Polignac number, because 666443513 - 2¹⁰ = 666442489 is a prime.

It is not a weakly prime, because it can be changed into another prime (666443543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333221756 + 333221757.

It is an arithmetic number, because the mean of its divisors is an integer number (333221757).

Almost surely, 2^666443513 is an apocalyptic number.

It is an amenable number.

666443513 is a deficient number, since it is larger than the sum of its proper divisors (1).

666443513 is an equidigital number, since it uses as much as digits as its factorization.

666443513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 155520, while the sum is 38.

The square root of 666443513 is about 25815.5672608603. The cubic root of 666443513 is about 873.4829825168.

The spelling of 666443513 in words is "six hundred sixty-six million, four hundred forty-three thousand, five hundred thirteen".