6464640 has 256 divisors, whose sum is σ = 26046720. Its totient is φ = 1327104.

The previous prime is 6464639. The next prime is 6464687. The reversal of 6464640 is 464646.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 6464598 and 6464607.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 174702 + ... + 174738.

It is an arithmetic number, because the mean of its divisors is an integer number (101745).

Almost surely, 2^6464640 is an apocalyptic number.

6464640 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 6464640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13023360).

6464640 is an abundant number, since it is smaller than the sum of its proper divisors (19582080).

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

6464640 is a wasteful number, since it uses less digits than its factorization.

6464640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 6464640 is about 2542.5656333711. The cubic root of 6464640 is about 186.2865279766.

The spelling of 6464640 in words is "six million, four hundred sixty-four thousand, six hundred forty".