644732047187 has 2 divisors, whose sum is σ = 644732047188. Its totient is φ = 644732047186.

The previous prime is 644732047139. The next prime is 644732047229. The reversal of 644732047187 is 781740237446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644732047187 - 2¹⁶ = 644731981651 is a prime.

It is a super-2 number, since 2×644732047187² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (644732047387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322366023593 + 322366023594.

It is an arithmetic number, because the mean of its divisors is an integer number (322366023594).

Almost surely, 2^644732047187 is an apocalyptic number.

644732047187 is a deficient number, since it is larger than the sum of its proper divisors (1).

644732047187 is an equidigital number, since it uses as much as digits as its factorization.

644732047187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6322176, while the sum is 53.

The spelling of 644732047187 in words is "six hundred forty-four billion, seven hundred thirty-two million, forty-seven thousand, one hundred eighty-seven".