646444202444640 has 384 divisors, whose sum is σ = 2266508766412800. Its totient is φ = 172083982878720.

The previous prime is 646444202444633. The next prime is 646444202444641. The reversal of 646444202444640 is 46444202444646.

646444202444640 is a `hidden beast` number, since 6 + 464 + 44 + 20 + 2 + 44 + 46 + 40 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646444202444641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13360953889 + ... + 13361002271.

It is an arithmetic number, because the mean of its divisors is an integer number (5902366579200).

Almost surely, 2^{646444202444640} is an apocalyptic number.

646444202444640 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 646444202444640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133254383206400).

646444202444640 is an abundant number, since it is smaller than the sum of its proper divisors (1620064563968160).

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

646444202444640 is a wasteful number, since it uses less digits than its factorization.

646444202444640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53747 (or 53733 counting only the distinct ones).

The product of its (nonzero) digits is 56623104, while the sum is 54.

The spelling of 646444202444640 in words is "six hundred forty-six trillion, four hundred forty-four billion, two hundred two million, four hundred forty-four thousand, six hundred forty".