21121221112 has 16 divisors (see below), whose sum is σ = 39678018840. Its totient is φ = 10540416096.

The previous prime is 21121221083. The next prime is 21121221113. The reversal of 21121221112 is 21112212112.

It is a super-2 number, since 2×21121221112² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121221113) 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, 2519863 + ... + 2528230.

Almost surely, 2^21121221112 is an apocalyptic number.

It is an amenable number.

21121221112 is a deficient number, since it is larger than the sum of its proper divisors (18556797728).

21121221112 is a wasteful number, since it uses less digits than its factorization.

21121221112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5048622 (or 5048618 counting only the distinct ones).

The product of its digits is 32, while the sum is 16.

Adding to 21121221112 its reverse (21112212112), we get a palindrome (42233433224).

It can be divided in two parts, 211212 and 21112, that added together give a square (232324 = 482²).

The spelling of 21121221112 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred twelve".