664064042440 has 16 divisors (see below), whose sum is σ = 1494144095580. Its totient is φ = 265625616960.

The previous prime is 664064042437. The next prime is 664064042449. The reversal of 664064042440 is 44240460466.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 662534137444 + 1529904996 = 813962^2 + 39114^2 .

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 16601601061 = 664064042440 / (6 + 6 + 4 + 0 + 6 + 4 + 0 + 4 + 2 + 4 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 664064042393 and 664064042402.

It is not an unprimeable number, because it can be changed into a prime (664064042449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8300800491 + ... + 8300800570.

Almost surely, 2^664064042440 is an apocalyptic number.

It is an amenable number.

664064042440 is an abundant number, since it is smaller than the sum of its proper divisors (830080053140).

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

664064042440 is a wasteful number, since it uses less digits than its factorization.

664064042440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16601601072 (or 16601601068 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 40.

The spelling of 664064042440 in words is "six hundred sixty-four billion, sixty-four million, forty-two thousand, four hundred forty".