21230020123123 has 4 divisors (see below), whose sum is σ = 24262880140720. Its totient is φ = 18197160105528.

The previous prime is 21230020123099. The next prime is 21230020123157. The reversal of 21230020123123 is 32132102003212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21230020123123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230020123094 and 21230020123103.

It is not an unprimeable number, because it can be changed into a prime (21230020123723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1516430008788 + ... + 1516430008801.

It is an arithmetic number, because the mean of its divisors is an integer number (6065720035180).

Almost surely, 2^{21230020123123} is an apocalyptic number.

21230020123123 is a deficient number, since it is larger than the sum of its proper divisors (3032860017597).

21230020123123 is an equidigital number, since it uses as much as digits as its factorization.

21230020123123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3032860017596.

The product of its (nonzero) digits is 864, while the sum is 22.

Adding to 21230020123123 its reverse (32132102003212), we get a palindrome (53362122126335).

The spelling of 21230020123123 in words is "twenty-one trillion, two hundred thirty billion, twenty million, one hundred twenty-three thousand, one hundred twenty-three".