22121081856 has 220 divisors, whose sum is σ = 66495042768. Its totient is φ = 7324950528.

The previous prime is 22121081839. The next prime is 22121081893. The reversal of 22121081856 is 65818012122.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 22121081856.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13850850 + ... + 13852446.

Almost surely, 2^22121081856 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 22121081856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33247521384).

22121081856 is an abundant number, since it is smaller than the sum of its proper divisors (44373960912).

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

22121081856 is a wasteful number, since it uses less digits than its factorization.

22121081856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1796 (or 1769 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

Adding to 22121081856 its reverse (65818012122), we get a palindrome (87939093978).

The spelling of 22121081856 in words is "twenty-two billion, one hundred twenty-one million, eighty-one thousand, eight hundred fifty-six".