195890243 has 2 divisors, whose sum is σ = 195890244. Its totient is φ = 195890242.

The previous prime is 195890237. The next prime is 195890263. The reversal of 195890243 is 342098591.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 195890243 - 2⁶ = 195890179 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 195890243.

It is not a weakly prime, because it can be changed into another prime (195890263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97945121 + 97945122.

It is an arithmetic number, because the mean of its divisors is an integer number (97945122).

Almost surely, 2^195890243 is an apocalyptic number.

195890243 is a deficient number, since it is larger than the sum of its proper divisors (1).

195890243 is an equidigital number, since it uses as much as digits as its factorization.

195890243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 195890243 is about 13996.0795582192. The cubic root of 195890243 is about 580.7701254074.

The spelling of 195890243 in words is "one hundred ninety-five million, eight hundred ninety thousand, two hundred forty-three".