263998409 has 2 divisors, whose sum is σ = 263998410. Its totient is φ = 263998408.

The previous prime is 263998403. The next prime is 263998421. The reversal of 263998409 is 904899362.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134676025 + 129322384 = 11605^2 + 11372^2 .

It is a cyclic number.

It is not a de Polignac number, because 263998409 - 2¹⁶ = 263932873 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (263998403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 131999204 + 131999205.

It is an arithmetic number, because the mean of its divisors is an integer number (131999205).

Almost surely, 2^263998409 is an apocalyptic number.

It is an amenable number.

263998409 is a deficient number, since it is larger than the sum of its proper divisors (1).

263998409 is an equidigital number, since it uses as much as digits as its factorization.

263998409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 839808, while the sum is 50.

The square root of 263998409 is about 16248.0278495576. The cubic root of 263998409 is about 641.5055773130.

The spelling of 263998409 in words is "two hundred sixty-three million, nine hundred ninety-eight thousand, four hundred nine".