21103012123 has 8 divisors (see below), whose sum is σ = 21721651200. Its totient is φ = 20486914560.

The previous prime is 21103012111. The next prime is 21103012181. The reversal of 21103012123 is 32121030112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21103012123 - 2²⁵ = 21069457691 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21103012097 and 21103012106.

It is not an unprimeable number, because it can be changed into a prime (21103012193) 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 7 ways as a sum of consecutive naturals, for example, 618523 + ... + 651748.

It is an arithmetic number, because the mean of its divisors is an integer number (2715206400).

Almost surely, 2^21103012123 is an apocalyptic number.

21103012123 is a deficient number, since it is larger than the sum of its proper divisors (618639077).

21103012123 is a wasteful number, since it uses less digits than its factorization.

21103012123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270757.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21103012123 its reverse (32121030112), we get a palindrome (53224042235).

The spelling of 21103012123 in words is "twenty-one billion, one hundred three million, twelve thousand, one hundred twenty-three".