21600223123 has 4 divisors (see below), whose sum is σ = 21737804320. Its totient is φ = 21462641928.

The previous prime is 21600223111. The next prime is 21600223129. The reversal of 21600223123 is 32132200612.

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 21600223123 - 2²⁵ = 21566668691 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21600223094 and 21600223103.

It is not an unprimeable number, because it can be changed into a prime (21600223129) 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, 68790363 + ... + 68790676.

It is an arithmetic number, because the mean of its divisors is an integer number (5434451080).

Almost surely, 2^21600223123 is an apocalyptic number.

21600223123 is a deficient number, since it is larger than the sum of its proper divisors (137581197).

21600223123 is a wasteful number, since it uses less digits than its factorization.

21600223123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137581196.

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

Adding to 21600223123 its reverse (32132200612), we get a palindrome (53732423735).

The spelling of 21600223123 in words is "twenty-one billion, six hundred million, two hundred twenty-three thousand, one hundred twenty-three".