644000424559 has 2 divisors, whose sum is σ = 644000424560. Its totient is φ = 644000424558.

The previous prime is 644000424467. The next prime is 644000424643. The reversal of 644000424559 is 955424000446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644000424559 - 2⁹ = 644000424047 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644000427559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322000212279 + 322000212280.

It is an arithmetic number, because the mean of its divisors is an integer number (322000212280).

Almost surely, 2^644000424559 is an apocalyptic number.

644000424559 is a deficient number, since it is larger than the sum of its proper divisors (1).

644000424559 is an equidigital number, since it uses as much as digits as its factorization.

644000424559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 691200, while the sum is 43.

The spelling of 644000424559 in words is "six hundred forty-four billion, four hundred twenty-four thousand, five hundred fifty-nine".