4447664640 has 400 divisors, whose sum is σ = 16175962440. Its totient is φ = 1167851520.

The previous prime is 4447664603. The next prime is 4447664651. The reversal of 4447664640 is 464667444.

It can be written as a sum of positive squares in 4 ways, for example, as 3434897664 + 1012766976 = 58608^2 + 31824^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18454920 + ... + 18455160.

Almost surely, 2^4447664640 is an apocalyptic number.

4447664640 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 4447664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8087981220).

4447664640 is an abundant number, since it is smaller than the sum of its proper divisors (11728297800).

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

4447664640 is an equidigital number, since it uses as much as digits as its factorization.

4447664640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 45.

The square root of 4447664640 is about 66690.8137602174. The cubic root of 4447664640 is about 1644.5383712819.

The spelling of 4447664640 in words is "four billion, four hundred forty-seven million, six hundred sixty-four thousand, six hundred forty".