21221031223 has 16 divisors (see below), whose sum is σ = 24308069184. Its totient is φ = 18147916800.

The previous prime is 21221031211. The next prime is 21221031233. The reversal of 21221031223 is 32213012212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221031223 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221031223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221031233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7985511 + ... + 7988167.

It is an arithmetic number, because the mean of its divisors is an integer number (1519254324).

Almost surely, 2^21221031223 is an apocalyptic number.

21221031223 is a deficient number, since it is larger than the sum of its proper divisors (3087037961).

21221031223 is a wasteful number, since it uses less digits than its factorization.

21221031223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4842.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21221031223 its reverse (32213012212), we get a palindrome (53434043435).

The spelling of 21221031223 in words is "twenty-one billion, two hundred twenty-one million, thirty-one thousand, two hundred twenty-three".