21080223 has 16 divisors (see below), whose sum is σ = 31417440. Its totient is φ = 13969152.

The previous prime is 21080219. The next prime is 21080231. The reversal of 21080223 is 32208012.

It is a happy number.

It is not a de Polignac number, because 21080223 - 2² = 21080219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21080196 and 21080205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080203) 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, 2415 + ... + 6927.

It is an arithmetic number, because the mean of its divisors is an integer number (1963590).

Almost surely, 2^21080223 is an apocalyptic number.

21080223 is a deficient number, since it is larger than the sum of its proper divisors (10337217).

21080223 is a wasteful number, since it uses less digits than its factorization.

21080223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4695 (or 4689 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21080223 is about 4591.3203983168. The cubic root of 21080223 is about 276.2432873754.

Adding to 21080223 its reverse (32208012), we get a palindrome (53288235).

The spelling of 21080223 in words is "twenty-one million, eighty thousand, two hundred twenty-three".