643604522004449 has 2 divisors, whose sum is σ = 643604522004450. Its totient is φ = 643604522004448.

The previous prime is 643604522004413. The next prime is 643604522004559. The reversal of 643604522004449 is 944400225406346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 483769819373824 + 159834702630625 = 21994768^2 + 12642575^2 .

It is a cyclic number.

It is not a de Polignac number, because 643604522004449 - 2¹² = 643604522000353 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643604522004449.

It is not a weakly prime, because it can be changed into another prime (643604522094449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321802261002224 + 321802261002225.

It is an arithmetic number, because the mean of its divisors is an integer number (321802261002225).

Almost surely, 2^{643604522004449} is an apocalyptic number.

It is an amenable number.

643604522004449 is a deficient number, since it is larger than the sum of its proper divisors (1).

643604522004449 is an equidigital number, since it uses as much as digits as its factorization.

643604522004449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19906560, while the sum is 53.

The spelling of 643604522004449 in words is "six hundred forty-three trillion, six hundred four billion, five hundred twenty-two million, four thousand, four hundred forty-nine".