21111222222012 has 192 divisors, whose sum is σ = 57829297913856. Its totient is φ = 5940458853120.

The previous prime is 21111222222011. The next prime is 21111222222031. The reversal of 21111222222012 is 21022222211112.

It is a self number, because there is not a number n which added to its sum of digits gives 21111222222012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111222222011) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8088543 + ... + 10375305.

It is an arithmetic number, because the mean of its divisors is an integer number (301194259968).

Almost surely, 2^{21111222222012} 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 21111222222012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28914648956928).

21111222222012 is an abundant number, since it is smaller than the sum of its proper divisors (36718075691844).

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

21111222222012 is a wasteful number, since it uses less digits than its factorization.

21111222222012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2286920 (or 2286918 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21111222222012 its reverse (21022222211112), we get a palindrome (42133444433124).

The spelling of 21111222222012 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, two hundred twenty-two thousand, twelve".