21120321111 has 16 divisors (see below), whose sum is σ = 29093803008. Its totient is φ = 13614307200.

The previous prime is 21120321077. The next prime is 21120321149. The reversal of 21120321111 is 11112302112.

It is not a de Polignac number, because 21120321111 - 2¹¹ = 21120319063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124321111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11935 + ... + 205871.

It is an arithmetic number, because the mean of its divisors is an integer number (1818362688).

Almost surely, 2^21120321111 is an apocalyptic number.

21120321111 is a deficient number, since it is larger than the sum of its proper divisors (7973481897).

21120321111 is a wasteful number, since it uses less digits than its factorization.

21120321111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195142.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21120321111 its reverse (11112302112), we get a palindrome (32232623223).

The spelling of 21120321111 in words is "twenty-one billion, one hundred twenty million, three hundred twenty-one thousand, one hundred eleven".