6440660446 has 16 divisors (see below), whose sum is σ = 10544430960. Its totient is φ = 2926137280.

The previous prime is 6440660377. The next prime is 6440660449.

It is a happy number.

6440660446 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6440660399 and 6440660408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440660449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25231 + ... + 116266.

It is an arithmetic number, because the mean of its divisors is an integer number (659026935).

Almost surely, 2^6440660446 is an apocalyptic number.

6440660446 is a deficient number, since it is larger than the sum of its proper divisors (4103770514).

6440660446 is a wasteful number, since it uses less digits than its factorization.

6440660446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143579.

The product of its (nonzero) digits is 331776, while the sum is 40.

The square root of 6440660446 is about 80253.7254337766. The cubic root of 6440660446 is about 1860.5590917648.

The spelling of 6440660446 in words is "six billion, four hundred forty million, six hundred sixty thousand, four hundred forty-six".