243242491 has 2 divisors, whose sum is σ = 243242492. Its totient is φ = 243242490.

The previous prime is 243242479. The next prime is 243242509. The reversal of 243242491 is 194242342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243242491 - 2¹⁵ = 243209723 is a prime.

It is not a weakly prime, because it can be changed into another prime (243242471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121621245 + 121621246.

It is an arithmetic number, because the mean of its divisors is an integer number (121621246).

Almost surely, 2^243242491 is an apocalyptic number.

243242491 is a deficient number, since it is larger than the sum of its proper divisors (1).

243242491 is an equidigital number, since it uses as much as digits as its factorization.

243242491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 31.

The square root of 243242491 is about 15596.2332311363. The cubic root of 243242491 is about 624.2326505854.

The spelling of 243242491 in words is "two hundred forty-three million, two hundred forty-two thousand, four hundred ninety-one".