644732047139 has 2 divisors, whose sum is σ = 644732047140. Its totient is φ = 644732047138.

The previous prime is 644732047111. The next prime is 644732047187. The reversal of 644732047139 is 931740237446.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644732047139 is a prime.

It is not a weakly prime, because it can be changed into another prime (644732047339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322366023569 + 322366023570.

It is an arithmetic number, because the mean of its divisors is an integer number (322366023570).

Almost surely, 2^644732047139 is an apocalyptic number.

644732047139 is a deficient number, since it is larger than the sum of its proper divisors (1).

644732047139 is an equidigital number, since it uses as much as digits as its factorization.

644732047139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3048192, while the sum is 50.

The spelling of 644732047139 in words is "six hundred forty-four billion, seven hundred thirty-two million, forty-seven thousand, one hundred thirty-nine".