4391989568640 has 640 divisors, whose sum is σ = 16325888990400. Its totient is φ = 1123810910208.

The previous prime is 4391989568621. The next prime is 4391989568647. The reversal of 4391989568640 is 468659891934.

4391989568640 is a `hidden beast` number, since 4 + 3 + 9 + 19 + 8 + 9 + 568 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is not an unprimeable number, because it can be changed into a prime (4391989568647) 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 79 ways as a sum of consecutive naturals, for example, 245038719 + ... + 245056641.

Almost surely, 2^{4391989568640} is an apocalyptic number.

4391989568640 is a gapful number since it is divisible by the number (40) 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 4391989568640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8162944495200).

4391989568640 is an abundant number, since it is smaller than the sum of its proper divisors (11933899421760).

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

4391989568640 is a wasteful number, since it uses less digits than its factorization.

4391989568640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18146 (or 18125 counting only the distinct ones).

The product of its (nonzero) digits is 403107840, while the sum is 72.

The spelling of 4391989568640 in words is "four trillion, three hundred ninety-one billion, nine hundred eighty-nine million, five hundred sixty-eight thousand, six hundred forty".