21010303123 has 4 divisors (see below), whose sum is σ = 21010684120. Its totient is φ = 21009922128.

The previous prime is 21010303109. The next prime is 21010303129. The reversal of 21010303123 is 32130301012.

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 21010303123 - 2⁹ = 21010302611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010303097 and 21010303106.

It is not an unprimeable number, because it can be changed into a prime (21010303129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 90165 + ... + 223942.

It is an arithmetic number, because the mean of its divisors is an integer number (5252671030).

Almost surely, 2^21010303123 is an apocalyptic number.

21010303123 is a deficient number, since it is larger than the sum of its proper divisors (380997).

21010303123 is an equidigital number, since it uses as much as digits as its factorization.

21010303123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380996.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21010303123 its reverse (32130301012), we get a palindrome (53140604135).

The spelling of 21010303123 in words is "twenty-one billion, ten million, three hundred three thousand, one hundred twenty-three".