21103033123 has 4 divisors (see below), whose sum is σ = 21103630600. Its totient is φ = 21102435648.

The previous prime is 21103033111. The next prime is 21103033129. The reversal of 21103033123 is 32133030112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21103033123 - 2¹³ = 21103024931 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21103033123.

It is not an unprimeable number, because it can be changed into a prime (21103033129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242190 + ... + 317587.

It is an arithmetic number, because the mean of its divisors is an integer number (5275907650).

Almost surely, 2^21103033123 is an apocalyptic number.

21103033123 is a deficient number, since it is larger than the sum of its proper divisors (597477).

21103033123 is an equidigital number, since it uses as much as digits as its factorization.

21103033123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 597476.

The product of its (nonzero) digits is 324, while the sum is 19.

Adding to 21103033123 its reverse (32133030112), we get a palindrome (53236063235).

The spelling of 21103033123 in words is "twenty-one billion, one hundred three million, thirty-three thousand, one hundred twenty-three".