6439904880 has 40 divisors (see below), whose sum is σ = 19963705872. Its totient is φ = 1717307904.

The previous prime is 6439904837. The next prime is 6439904881. The reversal of 6439904880 is 884099346.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6439904881) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 13416229 + ... + 13416708.

Almost surely, 2^6439904880 is an apocalyptic number.

6439904880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6439904880 is an abundant number, since it is smaller than the sum of its proper divisors (13523800992).

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

6439904880 is a wasteful number, since it uses less digits than its factorization.

6439904880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26832953 (or 26832947 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 51.

The square root of 6439904880 is about 80249.0179379162. The cubic root of 6439904880 is about 1860.4863336899.

The spelling of 6439904880 in words is "six billion, four hundred thirty-nine million, nine hundred four thousand, eight hundred eighty".