221343251 has 2 divisors, whose sum is σ = 221343252. Its totient is φ = 221343250.

The previous prime is 221343173. The next prime is 221343253. The reversal of 221343251 is 152343122.

221343251 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221343251 - 2¹⁴ = 221326867 is a prime.

Together with 221343253, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_12192422 and since 221343251 and 12192422 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (221343253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110671625 + 110671626.

It is an arithmetic number, because the mean of its divisors is an integer number (110671626).

Almost surely, 2^221343251 is an apocalyptic number.

221343251 is a deficient number, since it is larger than the sum of its proper divisors (1).

221343251 is an equidigital number, since it uses as much as digits as its factorization.

221343251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 23.

The square root of 221343251 is about 14877.6090484997. The cubic root of 221343251 is about 604.9072106859.

Adding to 221343251 its reverse (152343122), we get a palindrome (373686373).

The spelling of 221343251 in words is "two hundred twenty-one million, three hundred forty-three thousand, two hundred fifty-one".