644676953387 has 2 divisors, whose sum is σ = 644676953388. Its totient is φ = 644676953386.

The previous prime is 644676953369. The next prime is 644676953413. The reversal of 644676953387 is 783359676446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644676953387 - 2²⁸ = 644408517931 is a prime.

It is not a weakly prime, because it can be changed into another prime (644676953587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322338476693 + 322338476694.

It is an arithmetic number, because the mean of its divisors is an integer number (322338476694).

Almost surely, 2^644676953387 is an apocalyptic number.

644676953387 is a deficient number, since it is larger than the sum of its proper divisors (1).

644676953387 is an equidigital number, since it uses as much as digits as its factorization.

644676953387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 548674560, while the sum is 68.

The spelling of 644676953387 in words is "six hundred forty-four billion, six hundred seventy-six million, nine hundred fifty-three thousand, three hundred eighty-seven".