6444440646 has 64 divisors (see below), whose sum is σ = 14847584256. Its totient is φ = 1826640000.

The previous prime is 6444440617. The next prime is 6444440669. The reversal of 6444440646 is 6460444446.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6444440598 and 6444440607.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5456176 + ... + 5457356.

It is an arithmetic number, because the mean of its divisors is an integer number (231993504).

Almost surely, 2^6444440646 is an apocalyptic number.

6444440646 is an abundant number, since it is smaller than the sum of its proper divisors (8403143610).

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

6444440646 is a wasteful number, since it uses less digits than its factorization.

6444440646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2117.

The product of its (nonzero) digits is 884736, while the sum is 42.

The square root of 6444440646 is about 80277.2735336720. The cubic root of 6444440646 is about 1860.9230249348.

The spelling of 6444440646 in words is "six billion, four hundred forty-four million, four hundred forty thousand, six hundred forty-six".