21444223 has 2 divisors, whose sum is σ = 21444224. Its totient is φ = 21444222.

The previous prime is 21444193. The next prime is 21444233. The reversal of 21444223 is 32244412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21444223 - 2⁹ = 21443711 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21444194 and 21444203.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21444233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10722111 + 10722112.

It is an arithmetic number, because the mean of its divisors is an integer number (10722112).

Almost surely, 2^21444223 is an apocalyptic number.

21444223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21444223 is an equidigital number, since it uses as much as digits as its factorization.

21444223 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1536, while the sum is 22.

The square root of 21444223 is about 4630.7907532084. The cubic root of 21444223 is about 277.8242207797.

Adding to 21444223 its reverse (32244412), we get a palindrome (53688635).

The spelling of 21444223 in words is "twenty-one million, four hundred forty-four thousand, two hundred twenty-three".