644065429037760 has 672 divisors, whose sum is σ = 2348313649718400. Its totient is φ = 161734721863680.

The previous prime is 644065429037759. The next prime is 644065429037783. The reversal of 644065429037760 is 67730924560446.

644065429037760 is a `hidden beast` number, since 6 + 4 + 406 + 5 + 42 + 90 + 37 + 76 + 0 = 666.

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 95 ways as a sum of consecutive naturals, for example, 12043306701 + ... + 12043360179.

It is an arithmetic number, because the mean of its divisors is an integer number (3494514359700).

Almost surely, 2^{644065429037760} is an apocalyptic number.

644065429037760 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 644065429037760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1174156824859200).

644065429037760 is an abundant number, since it is smaller than the sum of its proper divisors (1704248220680640).

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

644065429037760 is a wasteful number, since it uses less digits than its factorization.

644065429037760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57089 (or 57076 counting only the distinct ones).

The product of its (nonzero) digits is 182891520, while the sum is 63.

The spelling of 644065429037760 in words is "six hundred forty-four trillion, sixty-five billion, four hundred twenty-nine million, thirty-seven thousand, seven hundred sixty".