644829685528387 has 2 divisors, whose sum is σ = 644829685528388. Its totient is φ = 644829685528386.

The previous prime is 644829685528333. The next prime is 644829685528429. The reversal of 644829685528387 is 783825586928446.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644829685528387 is a prime.

It is not a weakly prime, because it can be changed into another prime (644829685528307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322414842764193 + 322414842764194.

It is an arithmetic number, because the mean of its divisors is an integer number (322414842764194).

Almost surely, 2^{644829685528387} is an apocalyptic number.

644829685528387 is a deficient number, since it is larger than the sum of its proper divisors (1).

644829685528387 is an equidigital number, since it uses as much as digits as its factorization.

644829685528387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44590694400, while the sum is 85.

The spelling of 644829685528387 in words is "six hundred forty-four trillion, eight hundred twenty-nine billion, six hundred eighty-five million, five hundred twenty-eight thousand, three hundred eighty-seven".