644110243 has 6 divisors (see below), whose sum is σ = 749271156. Its totient is φ = 552094452.

The previous prime is 644110223. The next prime is 644110249. The reversal of 644110243 is 342011446.

644110243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644110243 - 2²⁵ = 610555811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644110249) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6572505 + ... + 6572602.

It is an arithmetic number, because the mean of its divisors is an integer number (124878526).

Almost surely, 2^644110243 is an apocalyptic number.

644110243 is a deficient number, since it is larger than the sum of its proper divisors (105160913).

644110243 is a wasteful number, since it uses less digits than its factorization.

644110243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13145121 (or 13145114 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 644110243 is about 25379.3270793376. The cubic root of 644110243 is about 863.6147844631.

Adding to 644110243 its reverse (342011446), we get a palindrome (986121689).

The spelling of 644110243 in words is "six hundred forty-four million, one hundred ten thousand, two hundred forty-three".