644246001216 has 336 divisors, whose sum is σ = 1987951929600. Its totient is φ = 206719672320.

The previous prime is 644246001163. The next prime is 644246001221. The reversal of 644246001216 is 612100642446.

644246001216 is a `hidden beast` number, since 6 + 4 + 4 + 24 + 600 + 1 + 21 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44580360 + ... + 44594808.

It is an arithmetic number, because the mean of its divisors is an integer number (5916523600).

Almost surely, 2^644246001216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644246001216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993975964800).

644246001216 is an abundant number, since it is smaller than the sum of its proper divisors (1343705928384).

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

644246001216 is a wasteful number, since it uses less digits than its factorization.

644246001216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14584 (or 14562 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 644246001216 in words is "six hundred forty-four billion, two hundred forty-six million, one thousand, two hundred sixteen".