644260325644743 has 4 divisors (see below), whose sum is σ = 859013767526328. Its totient is φ = 429506883763160.

The previous prime is 644260325644669. The next prime is 644260325644757. The reversal of 644260325644743 is 347446523062446.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 644260325644743 - 2³³ = 644251735710151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644260325644343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107376720940788 + ... + 107376720940793.

It is an arithmetic number, because the mean of its divisors is an integer number (214753441881582).

Almost surely, 2^{644260325644743} is an apocalyptic number.

644260325644743 is a deficient number, since it is larger than the sum of its proper divisors (214753441881585).

644260325644743 is a wasteful number, since it uses less digits than its factorization.

644260325644743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214753441881584.

The product of its (nonzero) digits is 278691840, while the sum is 60.

The spelling of 644260325644743 in words is "six hundred forty-four trillion, two hundred sixty billion, three hundred twenty-five million, six hundred forty-four thousand, seven hundred forty-three".