21112121331 has 18 divisors (see below), whose sum is σ = 35474109372. Its totient is φ = 12064069080.

The previous prime is 21112121269. The next prime is 21112121351. The reversal of 21112121331 is 13312121112.

21112121331 is a `hidden beast` number, since 211 + 1 + 2 + 121 + 331 = 666.

It is not a de Polignac number, because 21112121331 - 2¹⁰ = 21112120307 is a prime.

It is a super-2 number, since 2×21112121331² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21112121351) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 23936205 + ... + 23937086.

It is an arithmetic number, because the mean of its divisors is an integer number (1970783854).

Almost surely, 2^21112121331 is an apocalyptic number.

21112121331 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21112121331 is a deficient number, since it is larger than the sum of its proper divisors (14361988041).

21112121331 is a wasteful number, since it uses less digits than its factorization.

21112121331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47873311 (or 47873301 counting only the distinct ones).

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

Adding to 21112121331 its reverse (13312121112), we get a palindrome (34424242443).

The spelling of 21112121331 in words is "twenty-one billion, one hundred twelve million, one hundred twenty-one thousand, three hundred thirty-one".