21112131321 has 12 divisors (see below), whose sum is σ = 30520089600. Its totient is φ = 14063313240.

The previous prime is 21112131311. The next prime is 21112131361. The reversal of 21112131321 is 12313121112.

21112131321 is a `hidden beast` number, since 211 + 1 + 2 + 131 + 321 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21112131321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112131294 and 21112131303.

It is not an unprimeable number, because it can be changed into a prime (21112131311) 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, 941721 + ... + 963878.

It is an arithmetic number, because the mean of its divisors is an integer number (2543340800).

Almost surely, 2^21112131321 is an apocalyptic number.

It is an amenable number.

21112131321 is a deficient number, since it is larger than the sum of its proper divisors (9407958279).

21112131321 is a wasteful number, since it uses less digits than its factorization.

21112131321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906836 (or 1906833 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21112131321 its reverse (12313121112), we get a palindrome (33425252433).

The spelling of 21112131321 in words is "twenty-one billion, one hundred twelve million, one hundred thirty-one thousand, three hundred twenty-one".