644202343202497 has 2 divisors, whose sum is σ = 644202343202498. Its totient is φ = 644202343202496.

The previous prime is 644202343202437. The next prime is 644202343202519. The reversal of 644202343202497 is 794202343202446.

644202343202497 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 441933901906176 + 202268441296321 = 21022224^2 + 14222111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644202343202497 is a prime.

It is not a weakly prime, because it can be changed into another prime (644202343202417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322101171601248 + 322101171601249.

It is an arithmetic number, because the mean of its divisors is an integer number (322101171601249).

Almost surely, 2^{644202343202497} is an apocalyptic number.

It is an amenable number.

644202343202497 is a deficient number, since it is larger than the sum of its proper divisors (1).

644202343202497 is an equidigital number, since it uses as much as digits as its factorization.

644202343202497 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13934592, while the sum is 52.

The spelling of 644202343202497 in words is "six hundred forty-four trillion, two hundred two billion, three hundred forty-three million, two hundred two thousand, four hundred ninety-seven".