644307703445 has 64 divisors (see below), whose sum is σ = 913489920000. Its totient is φ = 436023459648.

The previous prime is 644307703439. The next prime is 644307703451. The reversal of 644307703445 is 544307703446.

644307703445 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (644307703439) and next prime (644307703451).

It is not a de Polignac number, because 644307703445 - 2²² = 644303509141 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644307703445.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 182057486 + ... + 182061024.

It is an arithmetic number, because the mean of its divisors is an integer number (14273280000).

Almost surely, 2^644307703445 is an apocalyptic number.

It is an amenable number.

644307703445 is a deficient number, since it is larger than the sum of its proper divisors (269182216555).

644307703445 is a wasteful number, since it uses less digits than its factorization.

644307703445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4927 (or 4913 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 47.

Subtracting from 644307703445 its reverse (544307703446), we obtain a palindrome (99999999999).

The spelling of 644307703445 in words is "six hundred forty-four billion, three hundred seven million, seven hundred three thousand, four hundred forty-five".