21116223 has 12 divisors (see below), whose sum is σ = 30553848. Its totient is φ = 14053200.

The previous prime is 21116219. The next prime is 21116257. The reversal of 21116223 is 32261112.

It is not a de Polignac number, because 21116223 - 2² = 21116219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21116196 and 21116205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21116203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4636 + ... + 7982.

It is an arithmetic number, because the mean of its divisors is an integer number (2546154).

Almost surely, 2^21116223 is an apocalyptic number.

21116223 is a deficient number, since it is larger than the sum of its proper divisors (9437625).

21116223 is a wasteful number, since it uses less digits than its factorization.

21116223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4054 (or 4051 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 21116223 is about 4595.2391667899. The cubic root of 21116223 is about 276.4004505233.

Adding to 21116223 its reverse (32261112), we get a palindrome (53377335).

The spelling of 21116223 in words is "twenty-one million, one hundred sixteen thousand, two hundred twenty-three".