644307703447 has 8 divisors (see below), whose sum is σ = 647584740000. Its totient is φ = 641031060384.

The previous prime is 644307703439. The next prime is 644307703451. The reversal of 644307703447 is 744307703446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644307703447 - 2³ = 644307703439 is a prime.

It is a super-2 number, since 2×644307703447² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 644307703447.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644307703147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3522453 + ... + 3700849.

It is an arithmetic number, because the mean of its divisors is an integer number (80948092500).

Almost surely, 2^644307703447 is an apocalyptic number.

644307703447 is a deficient number, since it is larger than the sum of its proper divisors (3277036553).

644307703447 is a wasteful number, since it uses less digits than its factorization.

644307703447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196745.

The product of its (nonzero) digits is 4741632, while the sum is 49.

Subtracting 644307703447 from its reverse (744307703446), we obtain a palindrome (99999999999).

The spelling of 644307703447 in words is "six hundred forty-four billion, three hundred seven million, seven hundred three thousand, four hundred forty-seven".