20731261776163 has 2 divisors, whose sum is σ = 20731261776164. Its totient is φ = 20731261776162.

The previous prime is 20731261776133. The next prime is 20731261776361. The reversal of 20731261776163 is 36167716213702.

Together with next prime (20731261776361) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20731261776163 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20731261776163.

It is not a weakly prime, because it can be changed into another prime (20731261776103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365630888081 + 10365630888082.

It is an arithmetic number, because the mean of its divisors is an integer number (10365630888082).

Almost surely, 2^{20731261776163} is an apocalyptic number.

20731261776163 is a deficient number, since it is larger than the sum of its proper divisors (1).

20731261776163 is an equidigital number, since it uses as much as digits as its factorization.

20731261776163 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2667168, while the sum is 52.

Adding to 20731261776163 its reverse (36167716213702), we get a palindrome (56898977989865).

The spelling of 20731261776163 in words is "twenty trillion, seven hundred thirty-one billion, two hundred sixty-one million, seven hundred seventy-six thousand, one hundred sixty-three".