243148981 has 2 divisors, whose sum is σ = 243148982. Its totient is φ = 243148980.

The previous prime is 243148973. The next prime is 243148999. The reversal of 243148981 is 189841342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 240560100 + 2588881 = 15510^2 + 1609^2 .

It is a cyclic number.

It is not a de Polignac number, because 243148981 - 2³ = 243148973 is a prime.

It is a super-2 number, since 2×243148981² = 118242853922676722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243148931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121574490 + 121574491.

It is an arithmetic number, because the mean of its divisors is an integer number (121574491).

Almost surely, 2^243148981 is an apocalyptic number.

It is an amenable number.

243148981 is a deficient number, since it is larger than the sum of its proper divisors (1).

243148981 is an equidigital number, since it uses as much as digits as its factorization.

243148981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 55296, while the sum is 40.

The square root of 243148981 is about 15593.2351037237. The cubic root of 243148981 is about 624.1526488328.

The spelling of 243148981 in words is "two hundred forty-three million, one hundred forty-eight thousand, nine hundred eighty-one".