21253122111 has 12 divisors (see below), whose sum is σ = 30684981768. Its totient is φ = 13078844064.

The previous prime is 21253122109. The next prime is 21253122113. The reversal of 21253122111 is 11122135212.

It is an interprime number because it is at equal distance from previous prime (21253122109) and next prime (21253122113).

It is not a de Polignac number, because 21253122111 - 2¹ = 21253122109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21253122113) 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 11 ways as a sum of consecutive naturals, for example, 20959180 + ... + 20960193.

It is an arithmetic number, because the mean of its divisors is an integer number (2557081814).

Almost surely, 2^21253122111 is an apocalyptic number.

21253122111 is a deficient number, since it is larger than the sum of its proper divisors (9431859657).

21253122111 is a wasteful number, since it uses less digits than its factorization.

21253122111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41919402 (or 41919389 counting only the distinct ones).

The product of its digits is 240, while the sum is 21.

Adding to 21253122111 its reverse (11122135212), we get a palindrome (32375257323).

The spelling of 21253122111 in words is "twenty-one billion, two hundred fifty-three million, one hundred twenty-two thousand, one hundred eleven".