21122222123 has 6 divisors (see below), whose sum is σ = 21875691084. Its totient is φ = 20393868824.

The previous prime is 21122222111. The next prime is 21122222131. The reversal of 21122222123 is 32122222112.

It is not a de Polignac number, because 21122222123 - 2⁶ = 21122222059 is a prime.

It is a super-2 number, since 2×21122222123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122222095 and 21122222104.

It is not an unprimeable number, because it can be changed into a prime (21122222923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12556961 + ... + 12558642.

It is an arithmetic number, because the mean of its divisors is an integer number (3645948514).

Almost surely, 2^21122222123 is an apocalyptic number.

21122222123 is a deficient number, since it is larger than the sum of its proper divisors (753468961).

21122222123 is an equidigital number, since it uses as much as digits as its factorization.

21122222123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25115661 (or 25115632 counting only the distinct ones).

The product of its digits is 384, while the sum is 20.

Adding to 21122222123 its reverse (32122222112), we get a palindrome (53244444235).

The spelling of 21122222123 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty-two thousand, one hundred twenty-three".