24216221 has 2 divisors, whose sum is σ = 24216222. Its totient is φ = 24216220.

The previous prime is 24216209. The next prime is 24216223. The reversal of 24216221 is 12261242.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12348196 + 11868025 = 3514^2 + 3445^2 .

It is a cyclic number.

It is not a de Polignac number, because 24216221 - 2¹⁴ = 24199837 is a prime.

Together with 24216223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 24216193 and 24216202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (24216223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12108110 + 12108111.

It is an arithmetic number, because the mean of its divisors is an integer number (12108111).

Almost surely, 2^24216221 is an apocalyptic number.

It is an amenable number.

24216221 is a deficient number, since it is larger than the sum of its proper divisors (1).

24216221 is an equidigital number, since it uses as much as digits as its factorization.

24216221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 20.

The square root of 24216221 is about 4920.9979678923. The cubic root of 24216221 is about 289.3135607629.

Adding to 24216221 its sum of digits (20), we get a square (24216241 = 4921²).

Adding to 24216221 its reverse (12261242), we get a palindrome (36477463).

The spelling of 24216221 in words is "twenty-four million, two hundred sixteen thousand, two hundred twenty-one".