6440445 has 32 divisors (see below), whose sum is σ = 12493440. Its totient is φ = 3121920.

The previous prime is 6440443. The next prime is 6440453. The reversal of 6440445 is 5440446.

It is not a de Polignac number, because 6440445 - 2¹ = 6440443 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440443) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 684 + ... + 3653.

It is an arithmetic number, because the mean of its divisors is an integer number (390420).

Almost surely, 2^6440445 is an apocalyptic number.

It is an amenable number.

6440445 is a deficient number, since it is larger than the sum of its proper divisors (6052995).

6440445 is a wasteful number, since it uses less digits than its factorization.

6440445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4362 (or 4356 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The square root of 6440445 is about 2537.8031838580. The cubic root of 6440445 is about 186.0538345731.

Subtracting from 6440445 its reverse (5440446), we obtain a palindrome (999999).

The spelling of 6440445 in words is "six million, four hundred forty thousand, four hundred forty-five".