6640256573 has 2 divisors, whose sum is σ = 6640256574. Its totient is φ = 6640256572.

The previous prime is 6640256563. The next prime is 6640256621. The reversal of 6640256573 is 3756520466.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6619124164 + 21132409 = 81358^2 + 4597^2 .

It is a cyclic number.

It is not a de Polignac number, because 6640256573 - 2⁶ = 6640256509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6640256543) 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, 3320128286 + 3320128287.

It is an arithmetic number, because the mean of its divisors is an integer number (3320128287).

Almost surely, 2^6640256573 is an apocalyptic number.

It is an amenable number.

6640256573 is a deficient number, since it is larger than the sum of its proper divisors (1).

6640256573 is an equidigital number, since it uses as much as digits as its factorization.

6640256573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 907200, while the sum is 44.

The square root of 6640256573 is about 81487.7694687982. The cubic root of 6640256573 is about 1879.5834837231.

The spelling of 6640256573 in words is "six billion, six hundred forty million, two hundred fifty-six thousand, five hundred seventy-three".