644546066603256 has 48 divisors (see below), whose sum is σ = 1746769644743760. Its totient is φ = 214710344536320.

The previous prime is 644546066603113. The next prime is 644546066603261. The reversal of 644546066603256 is 652306660645446.

644546066603256 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644546066603193 and 644546066603202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2882060980 + ... + 2882284611.

It is an arithmetic number, because the mean of its divisors is an integer number (36391034265495).

Almost surely, 2^{644546066603256} is an apocalyptic number.

It is an amenable number.

644546066603256 is an abundant number, since it is smaller than the sum of its proper divisors (1102223578140504).

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

644546066603256 is a wasteful number, since it uses less digits than its factorization.

644546066603256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5764347156 (or 5764347149 counting only the distinct ones).

The product of its (nonzero) digits is 447897600, while the sum is 63.

The spelling of 644546066603256 in words is "six hundred forty-four trillion, five hundred forty-six billion, sixty-six million, six hundred three thousand, two hundred fifty-six".