21231211223 has 8 divisors (see below), whose sum is σ = 21986423136. Its totient is φ = 20489133600.

The previous prime is 21231211219. The next prime is 21231211229. The reversal of 21231211223 is 32211213212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21231211223 - 2² = 21231211219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231211195 and 21231211204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231211229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3280283 + ... + 3286748.

It is an arithmetic number, because the mean of its divisors is an integer number (2748302892).

Almost surely, 2^21231211223 is an apocalyptic number.

21231211223 is a deficient number, since it is larger than the sum of its proper divisors (755211913).

21231211223 is an equidigital number, since it uses as much as digits as its factorization.

21231211223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6567145.

The product of its digits is 288, while the sum is 20.

Adding to 21231211223 its reverse (32211213212), we get a palindrome (53442424435).

The spelling of 21231211223 in words is "twenty-one billion, two hundred thirty-one million, two hundred eleven thousand, two hundred twenty-three".