644650647124 has 24 divisors (see below), whose sum is σ = 1230964445088. Its totient is φ = 292959270240.

The previous prime is 644650646993. The next prime is 644650647127. The reversal of 644650647124 is 421746056446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644650647127) 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 7 ways as a sum of consecutive naturals, for example, 1388947 + ... + 1794010.

It is an arithmetic number, because the mean of its divisors is an integer number (51290185212).

Almost surely, 2^644650647124 is an apocalyptic number.

It is an amenable number.

644650647124 is a deficient number, since it is larger than the sum of its proper divisors (586313797964).

644650647124 is a wasteful number, since it uses less digits than its factorization.

644650647124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3187575 (or 3187573 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 49.

The spelling of 644650647124 in words is "six hundred forty-four billion, six hundred fifty million, six hundred forty-seven thousand, one hundred twenty-four".