243845557 has 2 divisors, whose sum is σ = 243845558. Its totient is φ = 243845556.

The previous prime is 243845531. The next prime is 243845579. The reversal of 243845557 is 755548342.

243845557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 214153956 + 29691601 = 14634^2 + 5449^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243845557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243845507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121922778 + 121922779.

It is an arithmetic number, because the mean of its divisors is an integer number (121922779).

Almost surely, 2^243845557 is an apocalyptic number.

It is an amenable number.

243845557 is a deficient number, since it is larger than the sum of its proper divisors (1).

243845557 is an equidigital number, since it uses as much as digits as its factorization.

243845557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672000, while the sum is 43.

The square root of 243845557 is about 15615.5549693247. The cubic root of 243845557 is about 624.7481071336.

The spelling of 243845557 in words is "two hundred forty-three million, eight hundred forty-five thousand, five hundred fifty-seven".