640464444616 has 16 divisors (see below), whose sum is σ = 1201356463500. Its totient is φ = 320102721024.

The previous prime is 640464444611. The next prime is 640464444643. The reversal of 640464444616 is 616444464046.

It can be written as a sum of positive squares in 2 ways, for example, as 597513540100 + 42950904516 = 772990^2 + 207246^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 640464444616.

It is not an unprimeable number, because it can be changed into a prime (640464444611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16166641 + ... + 16206208.

Almost surely, 2^640464444616 is an apocalyptic number.

It is an amenable number.

640464444616 is a deficient number, since it is larger than the sum of its proper divisors (560892018884).

640464444616 is a wasteful number, since it uses less digits than its factorization.

640464444616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32375328 (or 32375324 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 49.

The spelling of 640464444616 in words is "six hundred forty billion, four hundred sixty-four million, four hundred forty-four thousand, six hundred sixteen".