21003321123123 has 4 divisors (see below), whose sum is σ = 28004428164168. Its totient is φ = 14002214082080.

The previous prime is 21003321123067. The next prime is 21003321123143. The reversal of 21003321123123 is 32132112330012.

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 21003321123123 - 2¹⁰ = 21003321122099 is a prime.

It is a super-2 number, since 2×21003321123123² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21003321123093 and 21003321123102.

It is not an unprimeable number, because it can be changed into a prime (21003321123143) 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, 3500553520518 + ... + 3500553520523.

It is an arithmetic number, because the mean of its divisors is an integer number (7001107041042).

Almost surely, 2^{21003321123123} is an apocalyptic number.

21003321123123 is a deficient number, since it is larger than the sum of its proper divisors (7001107041045).

21003321123123 is an equidigital number, since it uses as much as digits as its factorization.

21003321123123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7001107041044.

The product of its (nonzero) digits is 1296, while the sum is 24.

Adding to 21003321123123 its reverse (32132112330012), we get a palindrome (53135433453135).

The spelling of 21003321123123 in words is "twenty-one trillion, three billion, three hundred twenty-one million, one hundred twenty-three thousand, one hundred twenty-three".