216371 has 2 divisors, whose sum is σ = 216372. Its totient is φ = 216370.

The previous prime is 216347. The next prime is 216373. The reversal of 216371 is 173612.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216371 is a prime.

It is a Sophie Germain prime.

Together with 216373, 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 (216373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108185 + 108186.

It is an arithmetic number, because the mean of its divisors is an integer number (108186).

2²¹⁶³⁷¹ is an apocalyptic number.

216371 is a deficient number, since it is larger than the sum of its proper divisors (1).

216371 is an equidigital number, since it uses as much as digits as its factorization.

216371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 252, while the sum is 20.

The square root of 216371 is about 465.1569627556. The cubic root of 216371 is about 60.0343322031.

Adding to 216371 its reverse (173612), we get a palindrome (389983).

The spelling of 216371 in words is "two hundred sixteen thousand, three hundred seventy-one".