644008995144 has 48 divisors (see below), whose sum is σ = 1744262367120. Its totient is φ = 214660884960.

The previous prime is 644008995143. The next prime is 644008995151. The reversal of 644008995144 is 441599800446.

644008995144 is a `hidden beast` number, since 6 + 4 + 40 + 0 + 89 + 9 + 514 + 4 = 666.

It is not an unprimeable number, because it can be changed into a prime (644008995143) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1727239 + ... + 2066729.

It is an arithmetic number, because the mean of its divisors is an integer number (36338799315).

Almost surely, 2^644008995144 is an apocalyptic number.

It is an amenable number.

644008995144 is an abundant number, since it is smaller than the sum of its proper divisors (1100253371976).

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

644008995144 is a wasteful number, since it uses less digits than its factorization.

644008995144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365850 (or 365843 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 54.

The spelling of 644008995144 in words is "six hundred forty-four billion, eight million, nine hundred ninety-five thousand, one hundred forty-four".