243811901 has 2 divisors, whose sum is σ = 243811902. Its totient is φ = 243811900.

The previous prime is 243811859. The next prime is 243811969. The reversal of 243811901 is 109118342.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 172003225 + 71808676 = 13115^2 + 8474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243811901 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243811801) 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, 121905950 + 121905951.

It is an arithmetic number, because the mean of its divisors is an integer number (121905951).

Almost surely, 2^243811901 is an apocalyptic number.

It is an amenable number.

243811901 is a deficient number, since it is larger than the sum of its proper divisors (1).

243811901 is an equidigital number, since it uses as much as digits as its factorization.

243811901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 243811901 is about 15614.4772887215. The cubic root of 243811901 is about 624.7193628607.

The spelling of 243811901 in words is "two hundred forty-three million, eight hundred eleven thousand, nine hundred one".