21320331311 has 4 divisors (see below), whose sum is σ = 21339317592. Its totient is φ = 21301345032.

The previous prime is 21320331301. The next prime is 21320331317. The reversal of 21320331311 is 11313302312.

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 21320331311 - 2²⁶ = 21253222447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320331317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9491456 + ... + 9493701.

It is an arithmetic number, because the mean of its divisors is an integer number (5334829398).

Almost surely, 2^21320331311 is an apocalyptic number.

21320331311 is a deficient number, since it is larger than the sum of its proper divisors (18986281).

21320331311 is a wasteful number, since it uses less digits than its factorization.

21320331311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18986280.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21320331311 its reverse (11313302312), we get a palindrome (32633633623).

The spelling of 21320331311 in words is "twenty-one billion, three hundred twenty million, three hundred thirty-one thousand, three hundred eleven".