644586689236 has 12 divisors (see below), whose sum is σ = 1289173378528. Its totient is φ = 276251438232.

The previous prime is 644586689213. The next prime is 644586689269. The reversal of 644586689236 is 632986685446.

644586689236 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11510476566 + ... + 11510476621.

Almost surely, 2^644586689236 is an apocalyptic number.

It is an amenable number.

644586689236 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644586689236 is a wasteful number, since it uses less digits than its factorization.

644586689236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23020953198 (or 23020953196 counting only the distinct ones).

The product of its digits is 358318080, while the sum is 67.

The spelling of 644586689236 in words is "six hundred forty-four billion, five hundred eighty-six million, six hundred eighty-nine thousand, two hundred thirty-six".