243991193 has 2 divisors, whose sum is σ = 243991194. Its totient is φ = 243991192.

The previous prime is 243991169. The next prime is 243991201. The reversal of 243991193 is 391199342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 146119744 + 97871449 = 12088^2 + 9893^2 .

It is a cyclic number.

It is not a de Polignac number, because 243991193 - 2¹⁰ = 243990169 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243991193.

It is not a weakly prime, because it can be changed into another prime (243991393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121995596 + 121995597.

It is an arithmetic number, because the mean of its divisors is an integer number (121995597).

Almost surely, 2^243991193 is an apocalyptic number.

It is an amenable number.

243991193 is a deficient number, since it is larger than the sum of its proper divisors (1).

243991193 is an equidigital number, since it uses as much as digits as its factorization.

243991193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 41.

The square root of 243991193 is about 15620.2174440691. The cubic root of 243991193 is about 624.8724586682.

The spelling of 243991193 in words is "two hundred forty-three million, nine hundred ninety-one thousand, one hundred ninety-three".