6404320440 has 192 divisors, whose sum is σ = 23975976960. Its totient is φ = 1452245760.

The previous prime is 6404320409. The next prime is 6404320453. The reversal of 6404320440 is 440234046.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 310035 + ... + 330045.

It is an arithmetic number, because the mean of its divisors is an integer number (124874880).

Almost surely, 2^6404320440 is an apocalyptic number.

6404320440 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 6404320440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11987988480).

6404320440 is an abundant number, since it is smaller than the sum of its proper divisors (17571656520).

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

6404320440 is a wasteful number, since it uses less digits than its factorization.

6404320440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20162 (or 20155 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

The square root of 6404320440 is about 80026.9981943594. The cubic root of 6404320440 is about 1857.0532250120.

Adding to 6404320440 its reverse (440234046), we get a palindrome (6844554486).

The spelling of 6404320440 in words is "six billion, four hundred four million, three hundred twenty thousand, four hundred forty".