648005779321 has 2 divisors, whose sum is σ = 648005779322. Its totient is φ = 648005779320.

The previous prime is 648005779313. The next prime is 648005779331. The reversal of 648005779321 is 123977500846.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 624155301225 + 23850478096 = 790035^2 + 154436^2 .

It is a cyclic number.

It is not a de Polignac number, because 648005779321 - 2³ = 648005779313 is a prime.

It is a super-2 number, since 2×648005779321² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (648005779331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 324002889660 + 324002889661.

It is an arithmetic number, because the mean of its divisors is an integer number (324002889661).

It is a 1-persistent number, because it is pandigital, but 2⋅648005779321 = 1296011558642 is not.

Almost surely, 2^648005779321 is an apocalyptic number.

It is an amenable number.

648005779321 is a deficient number, since it is larger than the sum of its proper divisors (1).

648005779321 is an equidigital number, since it uses as much as digits as its factorization.

648005779321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2540160, while the sum is 52.

The spelling of 648005779321 in words is "six hundred forty-eight billion, five million, seven hundred seventy-nine thousand, three hundred twenty-one".