21203103123 has 24 divisors (see below), whose sum is σ = 31795657920. Its totient is φ = 13599358080.

The previous prime is 21203103113. The next prime is 21203103133. The reversal of 21203103123 is 32130130212.

21203103123 is a `hidden beast` number, since 21 + 20 + 310 + 312 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (21203103113) and next prime (21203103133).

It is not a de Polignac number, because 21203103123 - 2⁴ = 21203103107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21203103096 and 21203103105.

It is not an unprimeable number, because it can be changed into a prime (21203103113) 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, 71211 + ... + 217892.

It is an arithmetic number, because the mean of its divisors is an integer number (1324819080).

Almost surely, 2^21203103123 is an apocalyptic number.

21203103123 is a deficient number, since it is larger than the sum of its proper divisors (10592554797).

21203103123 is a wasteful number, since it uses less digits than its factorization.

21203103123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289419 (or 289416 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21203103123 its reverse (32130130212), we get a palindrome (53333233335).

The spelling of 21203103123 in words is "twenty-one billion, two hundred three million, one hundred three thousand, one hundred twenty-three".