664784840873 has 2 divisors, whose sum is σ = 664784840874. Its totient is φ = 664784840872.

The previous prime is 664784840861. The next prime is 664784840879. The reversal of 664784840873 is 378048487466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 367620304489 + 297164536384 = 606317^2 + 545128^2 .

It is a cyclic number.

It is not a de Polignac number, because 664784840873 - 2⁶ = 664784840809 is a prime.

It is a super-3 number, since 3×664784840873³ (a number of 36 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (664784840879) 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, 332392420436 + 332392420437.

It is an arithmetic number, because the mean of its divisors is an integer number (332392420437).

Almost surely, 2^664784840873 is an apocalyptic number.

It is an amenable number.

664784840873 is a deficient number, since it is larger than the sum of its proper divisors (1).

664784840873 is an equidigital number, since it uses as much as digits as its factorization.

664784840873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 173408256, while the sum is 65.

The spelling of 664784840873 in words is "six hundred sixty-four billion, seven hundred eighty-four million, eight hundred forty thousand, eight hundred seventy-three".