644043545324323 has 2 divisors, whose sum is σ = 644043545324324. Its totient is φ = 644043545324322.

The previous prime is 644043545324281. The next prime is 644043545324353. The reversal of 644043545324323 is 323423545340446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644043545324323 - 2⁹ = 644043545323811 is a prime.

It is not a weakly prime, because it can be changed into another prime (644043545324353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322021772662161 + 322021772662162.

It is an arithmetic number, because the mean of its divisors is an integer number (322021772662162).

Almost surely, 2^{644043545324323} is an apocalyptic number.

644043545324323 is a deficient number, since it is larger than the sum of its proper divisors (1).

644043545324323 is an equidigital number, since it uses as much as digits as its factorization.

644043545324323 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49766400, while the sum is 52.

The spelling of 644043545324323 in words is "six hundred forty-four trillion, forty-three billion, five hundred forty-five million, three hundred twenty-four thousand, three hundred twenty-three".