216943439 has 2 divisors, whose sum is σ = 216943440. Its totient is φ = 216943438.

The previous prime is 216943421. The next prime is 216943451. The reversal of 216943439 is 934349612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216943439 - 2⁸ = 216943183 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 216943396 and 216943405.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216943499) 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, 108471719 + 108471720.

It is an arithmetic number, because the mean of its divisors is an integer number (108471720).

Almost surely, 2^216943439 is an apocalyptic number.

216943439 is a deficient number, since it is larger than the sum of its proper divisors (1).

216943439 is an equidigital number, since it uses as much as digits as its factorization.

216943439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 41.

The square root of 216943439 is about 14728.9999321067. Note that the first 4 decimals coincide. The cubic root of 216943439 is about 600.8722858773.

The spelling of 216943439 in words is "two hundred sixteen million, nine hundred forty-three thousand, four hundred thirty-nine".