221144257 has 2 divisors, whose sum is σ = 221144258. Its totient is φ = 221144256.

The previous prime is 221144243. The next prime is 221144269. The reversal of 221144257 is 752441122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125417601 + 95726656 = 11199^2 + 9784^2 .

It is a cyclic number.

It is not a de Polignac number, because 221144257 - 2⁷ = 221144129 is a prime.

It is not a weakly prime, because it can be changed into another prime (221144207) 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, 110572128 + 110572129.

It is an arithmetic number, because the mean of its divisors is an integer number (110572129).

Almost surely, 2^221144257 is an apocalyptic number.

It is an amenable number.

221144257 is a deficient number, since it is larger than the sum of its proper divisors (1).

221144257 is an equidigital number, since it uses as much as digits as its factorization.

221144257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 28.

The square root of 221144257 is about 14870.9198437756. The cubic root of 221144257 is about 604.7258799611.

Adding to 221144257 its reverse (752441122), we get a palindrome (973585379).

The spelling of 221144257 in words is "two hundred twenty-one million, one hundred forty-four thousand, two hundred fifty-seven".