21100103123 has 16 divisors (see below), whose sum is σ = 23103522816. Its totient is φ = 19110997440.

The previous prime is 21100103113. The next prime is 21100103161. The reversal of 21100103123 is 32130100112.

It is a cyclic number.

It is not a de Polignac number, because 21100103123 - 2⁸ = 21100102867 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21100103098 and 21100103107.

It is not an unprimeable number, because it can be changed into a prime (21100103113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5742815 + ... + 5746487.

It is an arithmetic number, because the mean of its divisors is an integer number (1443970176).

Almost surely, 2^21100103123 is an apocalyptic number.

21100103123 is a deficient number, since it is larger than the sum of its proper divisors (2003419693).

21100103123 is a wasteful number, since it uses less digits than its factorization.

21100103123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5474.

The product of its (nonzero) digits is 36, while the sum is 14.

Adding to 21100103123 its reverse (32130100112), we get a palindrome (53230203235).

The spelling of 21100103123 in words is "twenty-one billion, one hundred million, one hundred three thousand, one hundred twenty-three".