648440 has 64 divisors (see below), whose sum is σ = 1663200. Its totient is φ = 225792.

The previous prime is 648437. The next prime is 648449. The reversal of 648440 is 44846.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 648440.

It is not an unprimeable number, because it can be changed into a prime (648449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15059 + ... + 15101.

2⁶⁴⁸⁴⁴⁰ 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 648440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (831600).

648440 is an abundant number, since it is smaller than the sum of its proper divisors (1014760).

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

648440 is a wasteful number, since it uses less digits than its factorization.

648440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96 (or 92 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 648440 is about 805.2577227199. The cubic root of 648440 is about 86.5545558923.

The spelling of 648440 in words is "six hundred forty-eight thousand, four hundred forty".