21012221112 has 16 divisors (see below), whose sum is σ = 52530552840. Its totient is φ = 7004073696.

The previous prime is 21012221059. The next prime is 21012221171. The reversal of 21012221112 is 21112221012.

It is a junction number, because it is equal to n+sod(n) for n = 21012221091 and 21012221100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 437754583 + ... + 437754630.

Almost surely, 2^21012221112 is an apocalyptic number.

It is an amenable number.

21012221112 is an abundant number, since it is smaller than the sum of its proper divisors (31518331728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012221112 is a wasteful number, since it uses less digits than its factorization.

21012221112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 875509222 (or 875509218 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21012221112 its reverse (21112221012), we get a palindrome (42124442124).

The spelling of 21012221112 in words is "twenty-one billion, twelve million, two hundred twenty-one thousand, one hundred twelve".