21022223 has 2 divisors, whose sum is σ = 21022224. Its totient is φ = 21022222.

The previous prime is 21022219. The next prime is 21022249. The reversal of 21022223 is 32222012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21022223 - 2² = 21022219 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 21022198 and 21022207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21022213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511111 + 10511112.

It is an arithmetic number, because the mean of its divisors is an integer number (10511112).

Almost surely, 2^21022223 is an apocalyptic number.

21022223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21022223 is an equidigital number, since it uses as much as digits as its factorization.

21022223 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21022223 is about 4584.9997818975. Note that the first 3 decimals coincide. The cubic root of 21022223 is about 275.9897032846.

Adding to 21022223 its reverse (32222012), we get a palindrome (53244235).

The spelling of 21022223 in words is "twenty-one million, twenty-two thousand, two hundred twenty-three".