6448640 has 80 divisors (see below), whose sum is σ = 16940880. Its totient is φ = 2334720.

The previous prime is 6448639. The next prime is 6448681. The reversal of 6448640 is 468446.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 6448597 and 6448606.

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 7 ways as a sum of consecutive naturals, for example, 28046 + ... + 28274.

It is an arithmetic number, because the mean of its divisors is an integer number (211761).

Almost surely, 2^6448640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6448640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8470440).

6448640 is an abundant number, since it is smaller than the sum of its proper divisors (10492240).

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

6448640 is a wasteful number, since it uses less digits than its factorization.

6448640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263 (or 247 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 6448640 is about 2539.4172559861. The cubic root of 6448640 is about 186.1327144712.

The spelling of 6448640 in words is "six million, four hundred forty-eight thousand, six hundred forty".