6446440 has 192 divisors, whose sum is σ = 20684160. Its totient is φ = 1774080.

The previous prime is 6446437. The next prime is 6446459. The reversal of 6446440 is 446446.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 6446399 and 6446408.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 280269 + ... + 280291.

It is an arithmetic number, because the mean of its divisors is an integer number (107730).

Almost surely, 2^6446440 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 6446440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10342080).

6446440 is an abundant number, since it is smaller than the sum of its proper divisors (14237720).

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

6446440 is a wasteful number, since it uses less digits than its factorization.

6446440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 61 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 6446440 is about 2538.9840487880. The cubic root of 6446440 is about 186.1115452248. Note that the first 3 decimals are identical.

It can be divided in two parts, 6446 and 440, that added together give a palindrome (6886).

The spelling of 6446440 in words is "six million, four hundred forty-six thousand, four hundred forty".