644716180944000 has 7168 divisors, whose sum is σ = 2993284581580800. Its totient is φ = 135981711360000.

The previous prime is 644716180943987. The next prime is 644716180944007. The reversal of 644716180944000 is 449081617446.

644716180944000 is a `hidden beast` number, since 6 + 4 + 4 + 7 + 16 + 180 + 9 + 440 + 0 + 0 = 666.

It is a super-2 number, since 2×644716180944000² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (644716180944007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 895 ways as a sum of consecutive naturals, for example, 1947783023835 + ... + 1947783024165.

Almost surely, 2^{644716180944000} is an apocalyptic number.

644716180944000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644716180944000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1496642290790400).

644716180944000 is an abundant number, since it is smaller than the sum of its proper divisors (2348568400636800).

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

644716180944000 is a wasteful number, since it uses less digits than its factorization.

644716180944000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 435 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The spelling of 644716180944000 in words is "six hundred forty-four trillion, seven hundred sixteen billion, one hundred eighty million, nine hundred forty-four thousand".