243984296681 has 2 divisors, whose sum is σ = 243984296682. Its totient is φ = 243984296680.

The previous prime is 243984296671. The next prime is 243984296683. The reversal of 243984296681 is 186692489342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179450515456 + 64533781225 = 423616^2 + 254035^2 .

It is a cyclic number.

It is not a de Polignac number, because 243984296681 - 2⁶ = 243984296617 is a prime.

It is a super-2 number, since 2×243984296681² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 243984296683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (243984296683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121992148340 + 121992148341.

It is an arithmetic number, because the mean of its divisors is an integer number (121992148341).

Almost surely, 2^243984296681 is an apocalyptic number.

It is an amenable number.

243984296681 is a deficient number, since it is larger than the sum of its proper divisors (1).

243984296681 is an equidigital number, since it uses as much as digits as its factorization.

243984296681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35831808, while the sum is 62.

The spelling of 243984296681 in words is "two hundred forty-three billion, nine hundred eighty-four million, two hundred ninety-six thousand, six hundred eighty-one".