23530021 has 2 divisors, whose sum is σ = 23530022. Its totient is φ = 23530020.

The previous prime is 23530019. The next prime is 23530027. The reversal of 23530021 is 12003532.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12173121 + 11356900 = 3489^2 + 3370^2 .

It is a cyclic number.

It is not a de Polignac number, because 23530021 - 2¹ = 23530019 is a prime.

Together with 23530019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 23529977 and 23530004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23530027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11765010 + 11765011.

It is an arithmetic number, because the mean of its divisors is an integer number (11765011).

Almost surely, 2^23530021 is an apocalyptic number.

It is an amenable number.

23530021 is a deficient number, since it is larger than the sum of its proper divisors (1).

23530021 is an equidigital number, since it uses as much as digits as its factorization.

23530021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 23530021 is about 4850.7752988569. The cubic root of 23530021 is about 286.5546354792.

Adding to 23530021 its reverse (12003532), we get a palindrome (35533553).

The spelling of 23530021 in words is "twenty-three million, five hundred thirty thousand, twenty-one".