243564131 has 2 divisors, whose sum is σ = 243564132. Its totient is φ = 243564130.

The previous prime is 243564121. The next prime is 243564133. The reversal of 243564131 is 131465342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243564131 is a prime.

It is a super-2 number, since 2×243564131² = 118646971819570322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 243564133, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 243564094 and 243564103.

It is not a weakly prime, because it can be changed into another prime (243564133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121782065 + 121782066.

It is an arithmetic number, because the mean of its divisors is an integer number (121782066).

Almost surely, 2^243564131 is an apocalyptic number.

243564131 is a deficient number, since it is larger than the sum of its proper divisors (1).

243564131 is an equidigital number, since it uses as much as digits as its factorization.

243564131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 29.

The square root of 243564131 is about 15606.5412888314. The cubic root of 243564131 is about 624.5076707342.

It can be divided in two parts, 2435 and 64131, that added together give a palindrome (66566).

The spelling of 243564131 in words is "two hundred forty-three million, five hundred sixty-four thousand, one hundred thirty-one".