6464440656 has 40 divisors (see below), whose sum is σ = 18555340160. Its totient is φ = 2154813408.

The previous prime is 6464440643. The next prime is 6464440673. The reversal of 6464440656 is 6560444646.

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, 7481560 + ... + 7482423.

It is an arithmetic number, because the mean of its divisors is an integer number (463883504).

Almost surely, 2^6464440656 is an apocalyptic number.

It is an amenable number.

6464440656 is an abundant number, since it is smaller than the sum of its proper divisors (12090899504).

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

6464440656 is a wasteful number, since it uses less digits than its factorization.

6464440656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14964000 (or 14963988 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 45.

The square root of 6464440656 is about 80401.7453541899. The cubic root of 6464440656 is about 1862.8461317633.

The spelling of 6464440656 in words is "six billion, four hundred sixty-four million, four hundred forty thousand, six hundred fifty-six".