640440506563 has 16 divisors (see below), whose sum is σ = 755202722400. Its totient is φ = 535434670080.

The previous prime is 640440506561. The next prime is 640440506569. The reversal of 640440506563 is 365605044046.

It is a cyclic number.

It is not a de Polignac number, because 640440506563 - 2¹ = 640440506561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640440506561) 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 15 ways as a sum of consecutive naturals, for example, 8286078 + ... + 8363011.

It is an arithmetic number, because the mean of its divisors is an integer number (47200170150).

Almost surely, 2^640440506563 is an apocalyptic number.

640440506563 is a deficient number, since it is larger than the sum of its proper divisors (114762215837).

640440506563 is a wasteful number, since it uses less digits than its factorization.

640440506563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16649382.

The product of its (nonzero) digits is 1036800, while the sum is 43.

The spelling of 640440506563 in words is "six hundred forty billion, four hundred forty million, five hundred six thousand, five hundred sixty-three".