21011222112 has 96 divisors (see below), whose sum is σ = 56628167904. Its totient is φ = 6817382400.

The previous prime is 21011222101. The next prime is 21011222149. The reversal of 21011222112 is 21122211012.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 21011222091 and 21011222100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1792912 + ... + 1804592.

It is an arithmetic number, because the mean of its divisors is an integer number (589876749).

Almost surely, 2^21011222112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011222112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28314083952).

21011222112 is an abundant number, since it is smaller than the sum of its proper divisors (35616945792).

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

21011222112 is a wasteful number, since it uses less digits than its factorization.

21011222112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12192 (or 12184 counting only the distinct ones).

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

Adding to 21011222112 its reverse (21122211012), we get a palindrome (42133433124).

The spelling of 21011222112 in words is "twenty-one billion, eleven million, two hundred twenty-two thousand, one hundred twelve".