243121279 has 2 divisors, whose sum is σ = 243121280. Its totient is φ = 243121278.

The previous prime is 243121259. The next prime is 243121289. The reversal of 243121279 is 972121342.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243121279 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 243121279.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243121259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560639 + 121560640.

It is an arithmetic number, because the mean of its divisors is an integer number (121560640).

Almost surely, 2^243121279 is an apocalyptic number.

243121279 is a deficient number, since it is larger than the sum of its proper divisors (1).

243121279 is an equidigital number, since it uses as much as digits as its factorization.

243121279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 31.

The square root of 243121279 is about 15592.3468086109. The cubic root of 243121279 is about 624.1289446641.

The spelling of 243121279 in words is "two hundred forty-three million, one hundred twenty-one thousand, two hundred seventy-nine".