21230023 has 2 divisors, whose sum is σ = 21230024. Its totient is φ = 21230022.

The previous prime is 21230017. The next prime is 21230047. The reversal of 21230023 is 32003212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21230023 - 2¹⁷ = 21098951 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21229985 and 21230012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21230123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615011 + 10615012.

It is an arithmetic number, because the mean of its divisors is an integer number (10615012).

Almost surely, 2^21230023 is an apocalyptic number.

21230023 is a deficient number, since it is larger than the sum of its proper divisors (1).

21230023 is an equidigital number, since it uses as much as digits as its factorization.

21230023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 13.

The square root of 21230023 is about 4607.6049092777. The cubic root of 21230023 is about 276.8960889555.

Adding to 21230023 its reverse (32003212), we get a palindrome (53233235).

The spelling of 21230023 in words is "twenty-one million, two hundred thirty thousand, twenty-three".