221440447 has 2 divisors, whose sum is σ = 221440448. Its totient is φ = 221440446.

The previous prime is 221440423. The next prime is 221440469. The reversal of 221440447 is 744044122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221440447 - 2⁷ = 221440319 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221440847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110720223 + 110720224.

It is an arithmetic number, because the mean of its divisors is an integer number (110720224).

Almost surely, 2^221440447 is an apocalyptic number.

221440447 is a deficient number, since it is larger than the sum of its proper divisors (1).

221440447 is an equidigital number, since it uses as much as digits as its factorization.

221440447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7168, while the sum is 28.

The square root of 221440447 is about 14880.8752094761. The cubic root of 221440447 is about 604.9957397874.

Adding to 221440447 its reverse (744044122), we get a palindrome (965484569).

The spelling of 221440447 in words is "two hundred twenty-one million, four hundred forty thousand, four hundred forty-seven".