23550221 has 2 divisors, whose sum is σ = 23550222. Its totient is φ = 23550220.

The previous prime is 23550199. The next prime is 23550223. The reversal of 23550221 is 12205532.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17547721 + 6002500 = 4189^2 + 2450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23550221 is a prime.

It is a super-2 number, since 2×23550221² = 1109225818297682, which contains 22 as substring.

Together with 23550223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 23550193 and 23550202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23550223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11775110 + 11775111.

It is an arithmetic number, because the mean of its divisors is an integer number (11775111).

Almost surely, 2^23550221 is an apocalyptic number.

It is an amenable number.

23550221 is a deficient number, since it is larger than the sum of its proper divisors (1).

23550221 is an equidigital number, since it uses as much as digits as its factorization.

23550221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 23550221 is about 4852.8569935657. The cubic root of 23550221 is about 286.6366122870.

Adding to 23550221 its reverse (12205532), we get a palindrome (35755753).

The spelling of 23550221 in words is "twenty-three million, five hundred fifty thousand, two hundred twenty-one".