20816216711789 has 2 divisors, whose sum is σ = 20816216711790. Its totient is φ = 20816216711788.

The previous prime is 20816216711761. The next prime is 20816216711893. The reversal of 20816216711789 is 98711761261802.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14567641630564 + 6248575081225 = 3816758^2 + 2499715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20816216711789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20816216711729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10408108355894 + 10408108355895.

It is an arithmetic number, because the mean of its divisors is an integer number (10408108355895).

Almost surely, 2^{20816216711789} is an apocalyptic number.

It is an amenable number.

20816216711789 is a deficient number, since it is larger than the sum of its proper divisors (1).

20816216711789 is an equidigital number, since it uses as much as digits as its factorization.

20816216711789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4064256, while the sum is 59.

The spelling of 20816216711789 in words is "twenty trillion, eight hundred sixteen billion, two hundred sixteen million, seven hundred eleven thousand, seven hundred eighty-nine".