242688409 has 2 divisors, whose sum is σ = 242688410. Its totient is φ = 242688408.

The previous prime is 242688371. The next prime is 242688473. The reversal of 242688409 is 904886242.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 151905625 + 90782784 = 12325^2 + 9528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242688409 is a prime.

It is not a weakly prime, because it can be changed into another prime (242685409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121344204 + 121344205.

It is an arithmetic number, because the mean of its divisors is an integer number (121344205).

Almost surely, 2^242688409 is an apocalyptic number.

It is an amenable number.

242688409 is a deficient number, since it is larger than the sum of its proper divisors (1).

242688409 is an equidigital number, since it uses as much as digits as its factorization.

242688409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 221184, while the sum is 43.

The square root of 242688409 is about 15578.4597762423. The cubic root of 242688409 is about 623.7583104449.

The spelling of 242688409 in words is "two hundred forty-two million, six hundred eighty-eight thousand, four hundred nine".