216503939 has 2 divisors, whose sum is σ = 216503940. Its totient is φ = 216503938.

The previous prime is 216503929. The next prime is 216503941. The reversal of 216503939 is 939305612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216503939 is a prime.

Together with 216503941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216503929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108251969 + 108251970.

It is an arithmetic number, because the mean of its divisors is an integer number (108251970).

Almost surely, 2^216503939 is an apocalyptic number.

216503939 is a deficient number, since it is larger than the sum of its proper divisors (1).

216503939 is an equidigital number, since it uses as much as digits as its factorization.

216503939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43740, while the sum is 38.

The square root of 216503939 is about 14714.0728216222. The cubic root of 216503939 is about 600.4662477797.

The spelling of 216503939 in words is "two hundred sixteen million, five hundred three thousand, nine hundred thirty-nine".