20311321111 has 4 divisors (see below), whose sum is σ = 20520716272. Its totient is φ = 20101925952.

The previous prime is 20311321087. The next prime is 20311321127. The reversal of 20311321111 is 11112311302.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20311321111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311321411) 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 3 ways as a sum of consecutive naturals, for example, 104697435 + ... + 104697628.

It is an arithmetic number, because the mean of its divisors is an integer number (5130179068).

Almost surely, 2^20311321111 is an apocalyptic number.

20311321111 is a deficient number, since it is larger than the sum of its proper divisors (209395161).

20311321111 is an equidigital number, since it uses as much as digits as its factorization.

20311321111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209395160.

The product of its (nonzero) digits is 36, while the sum is 16.

Adding to 20311321111 its reverse (11112311302), we get a palindrome (31423632413).

The spelling of 20311321111 in words is "twenty billion, three hundred eleven million, three hundred twenty-one thousand, one hundred eleven".