243116981 has 2 divisors, whose sum is σ = 243116982. Its totient is φ = 243116980.

The previous prime is 243116941. The next prime is 243117011. The reversal of 243116981 is 189611342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 185204881 + 57912100 = 13609^2 + 7610^2 .

It is a cyclic number.

It is not a de Polignac number, because 243116981 - 2²⁶ = 176008117 is a prime.

It is a super-2 number, since 2×243116981² = 118211732901108722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243116941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121558490 + 121558491.

It is an arithmetic number, because the mean of its divisors is an integer number (121558491).

Almost surely, 2^243116981 is an apocalyptic number.

It is an amenable number.

243116981 is a deficient number, since it is larger than the sum of its proper divisors (1).

243116981 is an equidigital number, since it uses as much as digits as its factorization.

243116981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 35.

The square root of 243116981 is about 15592.2089839766. The cubic root of 243116981 is about 624.1252667713.

The spelling of 243116981 in words is "two hundred forty-three million, one hundred sixteen thousand, nine hundred eighty-one".