242638421 has 2 divisors, whose sum is σ = 242638422. Its totient is φ = 242638420.

The previous prime is 242638397. The next prime is 242638441. The reversal of 242638421 is 124836242.

242638421 = 11014² + 11015².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121330225 + 121308196 = 11015^2 + 11014^2 .

It is a cyclic number.

It is not a de Polignac number, because 242638421 - 2¹⁰ = 242637397 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (242638441) 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, 121319210 + 121319211.

It is an arithmetic number, because the mean of its divisors is an integer number (121319211).

Almost surely, 2^242638421 is an apocalyptic number.

242638421 is the 11015-th centered square number.

It is an amenable number.

242638421 is a deficient number, since it is larger than the sum of its proper divisors (1).

242638421 is an equidigital number, since it uses as much as digits as its factorization.

242638421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18432, while the sum is 32.

The square root of 242638421 is about 15576.8552988079. The cubic root of 242638421 is about 623.7154810798.

The spelling of 242638421 in words is "two hundred forty-two million, six hundred thirty-eight thousand, four hundred twenty-one".