21022122222 has 96 divisors (see below), whose sum is σ = 48144784896. Its totient is φ = 6616209600.

The previous prime is 21022122211. The next prime is 21022122257. The reversal of 21022122222 is 22222122012.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21022122195 and 21022122204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 17951697 + ... + 17952867.

It is an arithmetic number, because the mean of its divisors is an integer number (501508176).

Almost surely, 2^21022122222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21022122222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24072392448).

21022122222 is an abundant number, since it is smaller than the sum of its proper divisors (27122662674).

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

21022122222 is a wasteful number, since it uses less digits than its factorization.

21022122222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1726 (or 1723 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21022122222 its reverse (22222122012), we get a palindrome (43244244234).

The spelling of 21022122222 in words is "twenty-one billion, twenty-two million, one hundred twenty-two thousand, two hundred twenty-two".