6444564480 has 180 divisors, whose sum is σ = 22343030892. Its totient is φ = 1718353920.

The previous prime is 6444564479. The next prime is 6444564481. The reversal of 6444564480 is 844654446.

6444564480 is a `hidden beast` number, since 6 + 4 + 4 + 4 + 564 + 4 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (6444564479) and next prime (6444564481).

It can be written as a sum of positive squares in 2 ways, for example, as 1719926784 + 4724637696 = 41472^2 + 68736^2 .

It is a tau number, because it is divible by the number of its divisors (180).

It is a super-2 number, since 2×6444564480² = 83064822673755340800, which contains 22 as substring.

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 (6444564481) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 732910 + ... + 741650.

Almost surely, 2^6444564480 is an apocalyptic number.

6444564480 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 6444564480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11171515446).

6444564480 is an abundant number, since it is smaller than the sum of its proper divisors (15898466412).

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

6444564480 is an equidigital number, since it uses as much as digits as its factorization.

6444564480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8780 (or 8751 counting only the distinct ones).

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

The square root of 6444564480 is about 80278.0448192406. The cubic root of 6444564480 is about 1860.9349444624.

The spelling of 6444564480 in words is "six billion, four hundred forty-four million, five hundred sixty-four thousand, four hundred eighty".