21101200123 has 2 divisors, whose sum is σ = 21101200124. Its totient is φ = 21101200122.

The previous prime is 21101200067. The next prime is 21101200129. The reversal of 21101200123 is 32100210112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21101200123 - 2²¹ = 21099102971 is a prime.

It is not a weakly prime, because it can be changed into another prime (21101200129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10550600061 + 10550600062.

It is an arithmetic number, because the mean of its divisors is an integer number (10550600062).

Almost surely, 2^21101200123 is an apocalyptic number.

21101200123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21101200123 is an equidigital number, since it uses as much as digits as its factorization.

21101200123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21101200123 its reverse (32100210112), we get a palindrome (53201410235).

The spelling of 21101200123 in words is "twenty-one billion, one hundred one million, two hundred thousand, one hundred twenty-three".