644450579 has 2 divisors, whose sum is σ = 644450580. Its totient is φ = 644450578.

The previous prime is 644450551. The next prime is 644450591. The reversal of 644450579 is 975054446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644450579 - 2²⁰ = 643402003 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (644450519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322225289 + 322225290.

It is an arithmetic number, because the mean of its divisors is an integer number (322225290).

Almost surely, 2^644450579 is an apocalyptic number.

644450579 is a deficient number, since it is larger than the sum of its proper divisors (1).

644450579 is an equidigital number, since it uses as much as digits as its factorization.

644450579 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 44.

The square root of 644450579 is about 25386.0311785832. The cubic root of 644450579 is about 863.7668637345.

The spelling of 644450579 in words is "six hundred forty-four million, four hundred fifty thousand, five hundred seventy-nine".