6444605440 has 504 divisors, whose sum is σ = 20506928760. Its totient is φ = 1932263424.

The previous prime is 6444605413. The next prime is 6444605449. The reversal of 6444605440 is 445064446.

It is a self number, because there is not a number n which added to its sum of digits gives 6444605440.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6444605449) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 339189751 + ... + 339189769.

Almost surely, 2^6444605440 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 6444605440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10253464380).

6444605440 is an abundant number, since it is smaller than the sum of its proper divisors (14062323320).

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

6444605440 is a wasteful number, since it uses less digits than its factorization.

6444605440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 37.

The square root of 6444605440 is about 80278.2999321735. The cubic root of 6444605440 is about 1860.9388869959.

Adding to 6444605440 its reverse (445064446), we get a palindrome (6889669886).

The spelling of 6444605440 in words is "six billion, four hundred forty-four million, six hundred five thousand, four hundred forty".