644673368176 has 20 divisors (see below), whose sum is σ = 1292125501800. Its totient is φ = 311221625792.

The previous prime is 644673368159. The next prime is 644673368179. The reversal of 644673368176 is 671863376446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644673368179) by changing a digit.

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, 694690666 + ... + 694691593.

It is an arithmetic number, because the mean of its divisors is an integer number (64606275090).

Almost surely, 2^644673368176 is an apocalyptic number.

It is an amenable number.

644673368176 is an abundant number, since it is smaller than the sum of its proper divisors (647452133624).

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

644673368176 is a wasteful number, since it uses less digits than its factorization.

644673368176 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389382296 (or 1389382290 counting only the distinct ones).

The product of its digits is 73156608, while the sum is 61.

The spelling of 644673368176 in words is "six hundred forty-four billion, six hundred seventy-three million, three hundred sixty-eight thousand, one hundred seventy-six".