21320111311 has 4 divisors (see below), whose sum is σ = 21531201624. Its totient is φ = 21109021000.

The previous prime is 21320111291. The next prime is 21320111363. The reversal of 21320111311 is 11311102312.

It is a happy number.

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 21320111311 - 2¹¹ = 21320109263 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 (21320111381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105545005 + ... + 105545206.

It is an arithmetic number, because the mean of its divisors is an integer number (5382800406).

Almost surely, 2^21320111311 is an apocalyptic number.

21320111311 is a deficient number, since it is larger than the sum of its proper divisors (211090313).

21320111311 is a wasteful number, since it uses less digits than its factorization.

21320111311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211090312.

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

Adding to 21320111311 its reverse (11311102312), we get a palindrome (32631213623).

The spelling of 21320111311 in words is "twenty-one billion, three hundred twenty million, one hundred eleven thousand, three hundred eleven".