216308231 has 2 divisors, whose sum is σ = 216308232. Its totient is φ = 216308230.

The previous prime is 216308207. The next prime is 216308233. The reversal of 216308231 is 132803612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216308231 - 2¹⁴ = 216291847 is a prime.

It is a super-2 number, since 2×216308231² = 93578501596698722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 216308233, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216308231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216308233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108154115 + 108154116.

It is an arithmetic number, because the mean of its divisors is an integer number (108154116).

Almost surely, 2^216308231 is an apocalyptic number.

216308231 is a deficient number, since it is larger than the sum of its proper divisors (1).

216308231 is an equidigital number, since it uses as much as digits as its factorization.

216308231 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 216308231 is about 14707.4209499830. The cubic root of 216308231 is about 600.2852634272.

The spelling of 216308231 in words is "two hundred sixteen million, three hundred eight thousand, two hundred thirty-one".