23213221 has 2 divisors, whose sum is σ = 23213222. Its totient is φ = 23213220.

The previous prime is 23213219. The next prime is 23213227. The reversal of 23213221 is 12231232.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17969121 + 5244100 = 4239^2 + 2290^2 .

It is a cyclic number.

It is not a de Polignac number, because 23213221 - 2¹ = 23213219 is a prime.

Together with 23213219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 23213195 and 23213204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23213227) 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, 11606610 + 11606611.

It is an arithmetic number, because the mean of its divisors is an integer number (11606611).

Almost surely, 2^23213221 is an apocalyptic number.

It is an amenable number.

23213221 is a deficient number, since it is larger than the sum of its proper divisors (1).

23213221 is an equidigital number, since it uses as much as digits as its factorization.

23213221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 16.

The square root of 23213221 is about 4818.0100664071. The cubic root of 23213221 is about 285.2627964865.

Adding to 23213221 its reverse (12231232), we get a palindrome (35444453).

The spelling of 23213221 in words is "twenty-three million, two hundred thirteen thousand, two hundred twenty-one".