640655322163 has 4 divisors (see below), whose sum is σ = 640749088008. Its totient is φ = 640561556320.

The previous prime is 640655322161. The next prime is 640655322191. The reversal of 640655322163 is 361223556046.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 640655322163 - 2¹ = 640655322161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640655322161) 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, 46872673 + ... + 46886338.

It is an arithmetic number, because the mean of its divisors is an integer number (160187272002).

Almost surely, 2^640655322163 is an apocalyptic number.

640655322163 is a deficient number, since it is larger than the sum of its proper divisors (93765845).

640655322163 is an equidigital number, since it uses as much as digits as its factorization.

640655322163 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93765844.

The product of its (nonzero) digits is 777600, while the sum is 43.

The spelling of 640655322163 in words is "six hundred forty billion, six hundred fifty-five million, three hundred twenty-two thousand, one hundred sixty-three".