6444463640 has 32 divisors (see below), whose sum is σ = 14853706560. Its totient is φ = 2514912000.

The previous prime is 6444463639. The next prime is 6444463651. The reversal of 6444463640 is 463644446.

It is a super-3 number, since 3×6444463640³ (a number of 30 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (41).

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 7 ways as a sum of consecutive naturals, for example, 1963136 + ... + 1966415.

It is an arithmetic number, because the mean of its divisors is an integer number (464178330).

Almost surely, 2^6444463640 is an apocalyptic number.

It is an amenable number.

6444463640 is an abundant number, since it is smaller than the sum of its proper divisors (8409242920).

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

6444463640 is a wasteful number, since it uses less digits than its factorization.

6444463640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3929603 (or 3929599 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 41.

The square root of 6444463640 is about 80277.4167496688. The cubic root of 6444463640 is about 1860.9252382126.

The spelling of 6444463640 in words is "six billion, four hundred forty-four million, four hundred sixty-three thousand, six hundred forty".