21304220123 has 4 divisors (see below), whose sum is σ = 22557409560. Its totient is φ = 20051030688.

The previous prime is 21304220111. The next prime is 21304220159. The reversal of 21304220123 is 32102240312.

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 21304220123 - 2¹⁰ = 21304219099 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21304220095 and 21304220104.

It is not an unprimeable number, because it can be changed into a prime (21304220023) 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, 626594693 + ... + 626594726.

It is an arithmetic number, because the mean of its divisors is an integer number (5639352390).

Almost surely, 2^21304220123 is an apocalyptic number.

21304220123 is a deficient number, since it is larger than the sum of its proper divisors (1253189437).

21304220123 is a wasteful number, since it uses less digits than its factorization.

21304220123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253189436.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21304220123 its reverse (32102240312), we get a palindrome (53406460435).

The spelling of 21304220123 in words is "twenty-one billion, three hundred four million, two hundred twenty thousand, one hundred twenty-three".