640265564561 has 8 divisors (see below), whose sum is σ = 738570692160. Its totient is φ = 543670091568.

The previous prime is 640265564509. The next prime is 640265564623. The reversal of 640265564561 is 165465562046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640265564561 - 2¹⁴ = 640265548177 is a prime.

It is not an unprimeable number, because it can be changed into a prime (640265564161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 427412846 + ... + 427414343.

It is an arithmetic number, because the mean of its divisors is an integer number (92321336520).

Almost surely, 2^640265564561 is an apocalyptic number.

It is an amenable number.

640265564561 is a deficient number, since it is larger than the sum of its proper divisors (98305127599).

640265564561 is a wasteful number, since it uses less digits than its factorization.

640265564561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 854827303.

The product of its (nonzero) digits is 5184000, while the sum is 50.

The spelling of 640265564561 in words is "six hundred forty billion, two hundred sixty-five million, five hundred sixty-four thousand, five hundred sixty-one".