216239999 has 2 divisors, whose sum is σ = 216240000. Its totient is φ = 216239998.

The previous prime is 216239987. The next prime is 216240023. The reversal of 216239999 is 999932612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216239999 - 2¹⁶ = 216174463 is a prime.

It is a super-3 number, since 3×216239999³ (a number of 26 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216239909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108119999 + 108120000.

It is an arithmetic number, because the mean of its divisors is an integer number (108120000).

Almost surely, 2^216239999 is an apocalyptic number.

216239999 is a deficient number, since it is larger than the sum of its proper divisors (1).

216239999 is an equidigital number, since it uses as much as digits as its factorization.

216239999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 472392, while the sum is 50.

The square root of 216239999 is about 14705.1011217196. The cubic root of 216239999 is about 600.2221390432. Note that the first 3 decimals are identical.

The spelling of 216239999 in words is "two hundred sixteen million, two hundred thirty-nine thousand, nine hundred ninety-nine".