243215191 has 2 divisors, whose sum is σ = 243215192. Its totient is φ = 243215190.

The previous prime is 243215131. The next prime is 243215201. The reversal of 243215191 is 191512342.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 243215191 - 2⁹ = 243214679 is a prime.

It is a super-3 number, since 3×243215191³ (a number of 26 digits) contains 333 as substring.

It is equal to p_13328029 and since 243215191 and 13328029 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243215101) 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, 121607595 + 121607596.

It is an arithmetic number, because the mean of its divisors is an integer number (121607596).

Almost surely, 2^243215191 is an apocalyptic number.

243215191 is a deficient number, since it is larger than the sum of its proper divisors (1).

243215191 is an equidigital number, since it uses as much as digits as its factorization.

243215191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 28.

The square root of 243215191 is about 15595.3579952497. The cubic root of 243215191 is about 624.2092964024.

The spelling of 243215191 in words is "two hundred forty-three million, two hundred fifteen thousand, one hundred ninety-one".