21224023 has 2 divisors, whose sum is σ = 21224024. Its totient is φ = 21224022.

The previous prime is 21224003. The next prime is 21224053. The reversal of 21224023 is 32042212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21224023 - 2⁹ = 21223511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21223988 and 21224006.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21224003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612011 + 10612012.

It is an arithmetic number, because the mean of its divisors is an integer number (10612012).

Almost surely, 2^21224023 is an apocalyptic number.

21224023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21224023 is an equidigital number, since it uses as much as digits as its factorization.

21224023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21224023 is about 4606.9537657763. The cubic root of 21224023 is about 276.8700011667.

Adding to 21224023 its reverse (32042212), we get a palindrome (53266235).

The spelling of 21224023 in words is "twenty-one million, two hundred twenty-four thousand, twenty-three".