21321003123 has 24 divisors (see below), whose sum is σ = 35202881376. Its totient is φ = 12181248000.

The previous prime is 21321003113. The next prime is 21321003157. The reversal of 21321003123 is 32130012312.

It is not a de Polignac number, because 21321003123 - 2⁴ = 21321003107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21321003096 and 21321003105.

It is not an unprimeable number, because it can be changed into a prime (21321003113) 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 23 ways as a sum of consecutive naturals, for example, 364723 + ... + 419123.

It is an arithmetic number, because the mean of its divisors is an integer number (1466786724).

Almost surely, 2^21321003123 is an apocalyptic number.

21321003123 is a deficient number, since it is larger than the sum of its proper divisors (13881878253).

21321003123 is a wasteful number, since it uses less digits than its factorization.

21321003123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60635 (or 60632 counting only the distinct ones).

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

Adding to 21321003123 its reverse (32130012312), we get a palindrome (53451015435).

The spelling of 21321003123 in words is "twenty-one billion, three hundred twenty-one million, three thousand, one hundred twenty-three".