6444644580 has 384 divisors, whose sum is σ = 24385536000. Its totient is φ = 1392629760.

The previous prime is 6444644543. The next prime is 6444644581. The reversal of 6444644580 is 854464446.

6444644580 is a `hidden beast` number, since 6 + 4 + 4 + 4 + 64 + 4 + 580 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (6444644581) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1916941 + ... + 1920299.

It is an arithmetic number, because the mean of its divisors is an integer number (63504000).

Almost surely, 2^6444644580 is an apocalyptic number.

6444644580 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 6444644580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12192768000).

6444644580 is an abundant number, since it is smaller than the sum of its proper divisors (17940891420).

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

6444644580 is a wasteful number, since it uses less digits than its factorization.

6444644580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3424 (or 3416 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 45.

The square root of 6444644580 is about 80278.5437087644. The cubic root of 6444644580 is about 1860.9426543329.

It can be divided in two parts, 64 and 44644580, that added together give a palindrome (44644644).

The spelling of 6444644580 in words is "six billion, four hundred forty-four million, six hundred forty-four thousand, five hundred eighty".