644625677832 has 64 divisors (see below), whose sum is σ = 1681768068480. Its totient is φ = 205516219392.

The previous prime is 644625677827. The next prime is 644625677849. The reversal of 644625677832 is 238776526446.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8048608 + ... + 8128304.

It is an arithmetic number, because the mean of its divisors is an integer number (26277626070).

Almost surely, 2^644625677832 is an apocalyptic number.

It is an amenable number.

644625677832 is an abundant number, since it is smaller than the sum of its proper divisors (1037142390648).

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

644625677832 is a wasteful number, since it uses less digits than its factorization.

644625677832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94382 (or 94378 counting only the distinct ones).

The product of its digits is 81285120, while the sum is 60.

The spelling of 644625677832 in words is "six hundred forty-four billion, six hundred twenty-five million, six hundred seventy-seven thousand, eight hundred thirty-two".