243982813 has 2 divisors, whose sum is σ = 243982814. Its totient is φ = 243982812.

The previous prime is 243982811. The next prime is 243982831. The reversal of 243982813 is 318289342.

Together with next prime (243982831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210308004 + 33674809 = 14502^2 + 5803^2 .

It is a cyclic number.

It is not a de Polignac number, because 243982813 - 2¹ = 243982811 is a prime.

It is a super-2 number, since 2×243982813² = 119055226078785938, which contains 22 as substring.

Together with 243982811, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243982811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121991406 + 121991407.

It is an arithmetic number, because the mean of its divisors is an integer number (121991407).

Almost surely, 2^243982813 is an apocalyptic number.

It is an amenable number.

243982813 is a deficient number, since it is larger than the sum of its proper divisors (1).

243982813 is an equidigital number, since it uses as much as digits as its factorization.

243982813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 40.

The square root of 243982813 is about 15619.9491996613. The cubic root of 243982813 is about 624.8653047336.

The spelling of 243982813 in words is "two hundred forty-three million, nine hundred eighty-two thousand, eight hundred thirteen".