20311323181 has 2 divisors, whose sum is σ = 20311323182. Its totient is φ = 20311323180.

The previous prime is 20311323169. The next prime is 20311323191. The reversal of 20311323181 is 18132311302.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20309100100 + 2223081 = 142510^2 + 1491^2 .

It is a cyclic number.

It is not a de Polignac number, because 20311323181 - 2¹¹ = 20311321133 is a prime.

It is a super-2 number, since 2×20311323181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20311323191) 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 as a sum of consecutive naturals, namely, 10155661590 + 10155661591.

It is an arithmetic number, because the mean of its divisors is an integer number (10155661591).

Almost surely, 2^20311323181 is an apocalyptic number.

It is an amenable number.

20311323181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20311323181 is an equidigital number, since it uses as much as digits as its factorization.

20311323181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

Adding to 20311323181 its reverse (18132311302), we get a palindrome (38443634483).

The spelling of 20311323181 in words is "twenty billion, three hundred eleven million, three hundred twenty-three thousand, one hundred eighty-one".