21042200123 has 12 divisors (see below), whose sum is σ = 25380543600. Its totient is φ = 17086897296.

The previous prime is 21042200099. The next prime is 21042200129. The reversal of 21042200123 is 32100224012.

It is not a de Polignac number, because 21042200123 - 2⁶ = 21042200059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042200129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4160948 + ... + 4166001.

It is an arithmetic number, because the mean of its divisors is an integer number (2115045300).

Almost surely, 2^21042200123 is an apocalyptic number.

21042200123 is a deficient number, since it is larger than the sum of its proper divisors (4338343477).

21042200123 is an equidigital number, since it uses as much as digits as its factorization.

21042200123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8326994 (or 8326975 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21042200123 its reverse (32100224012), we get a palindrome (53142424135).

The spelling of 21042200123 in words is "twenty-one billion, forty-two million, two hundred thousand, one hundred twenty-three".