21122122122 has 96 divisors (see below), whose sum is σ = 48839656320. Its totient is φ = 6578409600.

The previous prime is 21122122097. The next prime is 21122122123. The reversal of 21122122122 is 22122122112.

It is a happy number.

It is a super-2 number, since 2×21122122122² (a number of 21 digits) contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21122122095 and 21122122104.

It is not an unprimeable number, because it can be changed into a prime (21122122123) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10119763 + ... + 10121849.

It is an arithmetic number, because the mean of its divisors is an integer number (508746420).

Almost surely, 2^21122122122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21122122122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24419828160).

21122122122 is an abundant number, since it is smaller than the sum of its proper divisors (27717534198).

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

21122122122 is a wasteful number, since it uses less digits than its factorization.

21122122122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2508 (or 2505 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 21122122122 its reverse (22122122112), we get a palindrome (43244244234).

The spelling of 21122122122 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty-two thousand, one hundred twenty-two".