6445671287440 has 640 divisors, whose sum is σ = 19725091799040. Its totient is φ = 1916361216000.

The previous prime is 6445671287413. The next prime is 6445671287521. The reversal of 6445671287440 is 447821765446.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1640535396 + ... + 1640539324.

It is an arithmetic number, because the mean of its divisors is an integer number (30820455936).

Almost surely, 2^{6445671287440} 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 6445671287440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9862545899520).

6445671287440 is an abundant number, since it is smaller than the sum of its proper divisors (13279420511600).

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

6445671287440 is a wasteful number, since it uses less digits than its factorization.

6445671287440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4084 (or 4056 counting only the distinct ones).

The product of its (nonzero) digits is 36126720, while the sum is 58.

The spelling of 6445671287440 in words is "six trillion, four hundred forty-five billion, six hundred seventy-one million, two hundred eighty-seven thousand, four hundred forty".