21031324123123 has 4 divisors (see below), whose sum is σ = 21031334280000. Its totient is φ = 21031313966248.

The previous prime is 21031324123109. The next prime is 21031324123151. The reversal of 21031324123123 is 32132142313012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21031324123123 - 2¹⁷ = 21031323992051 is a prime.

It is a super-4 number, since 4×21031324123123⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21031324123091 and 21031324123100.

It is not an unprimeable number, because it can be changed into a prime (21031324123163) 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, 733123 + ... + 6526876.

It is an arithmetic number, because the mean of its divisors is an integer number (5257833570000).

Almost surely, 2^{21031324123123} is an apocalyptic number.

21031324123123 is a deficient number, since it is larger than the sum of its proper divisors (10156877).

21031324123123 is an equidigital number, since it uses as much as digits as its factorization.

21031324123123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10156876.

The product of its (nonzero) digits is 5184, while the sum is 28.

Adding to 21031324123123 its reverse (32132142313012), we get a palindrome (53163466436135).

The spelling of 21031324123123 in words is "twenty-one trillion, thirty-one billion, three hundred twenty-four million, one hundred twenty-three thousand, one hundred twenty-three".