242910721 has 2 divisors, whose sum is σ = 242910722. Its totient is φ = 242910720.

The previous prime is 242910683. The next prime is 242910737. The reversal of 242910721 is 127019242.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 242892225 + 18496 = 15585^2 + 136^2 .

It is a cyclic number.

It is not a de Polignac number, because 242910721 - 2⁹ = 242910209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 242910721.

It is not a weakly prime, because it can be changed into another prime (242910791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121455360 + 121455361.

It is an arithmetic number, because the mean of its divisors is an integer number (121455361).

Almost surely, 2^242910721 is an apocalyptic number.

It is an amenable number.

242910721 is a deficient number, since it is larger than the sum of its proper divisors (1).

242910721 is an equidigital number, since it uses as much as digits as its factorization.

242910721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 242910721 is about 15585.5933797851. The cubic root of 242910721 is about 623.9487145899.

Adding to 242910721 its reverse (127019242), we get a palindrome (369929963).

The spelling of 242910721 in words is "two hundred forty-two million, nine hundred ten thousand, seven hundred twenty-one".