223308721 has 2 divisors, whose sum is σ = 223308722. Its totient is φ = 223308720.

The previous prime is 223308713. The next prime is 223308731. The reversal of 223308721 is 127803322.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203461696 + 19847025 = 14264^2 + 4455^2 .

It is a cyclic number.

It is not a de Polignac number, because 223308721 - 2³ = 223308713 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 223308721.

It is not a weakly prime, because it can be changed into another prime (223308731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111654360 + 111654361.

It is an arithmetic number, because the mean of its divisors is an integer number (111654361).

Almost surely, 2^223308721 is an apocalyptic number.

It is an amenable number.

223308721 is a deficient number, since it is larger than the sum of its proper divisors (1).

223308721 is an equidigital number, since it uses as much as digits as its factorization.

223308721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 223308721 is about 14943.5176916280. The cubic root of 223308721 is about 606.6924094794.

The spelling of 223308721 in words is "two hundred twenty-three million, three hundred eight thousand, seven hundred twenty-one".