21111222123 has 24 divisors (see below), whose sum is σ = 30568775328. Its totient is φ = 14039682432.

The previous prime is 21111222113. The next prime is 21111222151. The reversal of 21111222123 is 32122211112.

It is not a de Polignac number, because 21111222123 - 2⁵ = 21111222091 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111222096 and 21111222105.

It is not an unprimeable number, because it can be changed into a prime (21111222113) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9804415 + ... + 9806567.

It is an arithmetic number, because the mean of its divisors is an integer number (1273698972).

Almost surely, 2^21111222123 is an apocalyptic number.

21111222123 is a deficient number, since it is larger than the sum of its proper divisors (9457553205).

21111222123 is a wasteful number, since it uses less digits than its factorization.

21111222123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4323 (or 4320 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 21111222123 its reverse (32122211112), we get a palindrome (53233433235).

The spelling of 21111222123 in words is "twenty-one billion, one hundred eleven million, two hundred twenty-two thousand, one hundred twenty-three".