211663 has 2 divisors, whose sum is σ = 211664. Its totient is φ = 211662.

The previous prime is 211661. The next prime is 211681. The reversal of 211663 is 366112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 211663 - 2¹ = 211661 is a prime.

Together with 211661, it forms a pair of twin primes.

211663 is a lucky number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 211663.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105831 + 105832.

It is an arithmetic number, because the mean of its divisors is an integer number (105832).

2²¹¹⁶⁶³ is an apocalyptic number.

211663 is a deficient number, since it is larger than the sum of its proper divisors (1).

211663 is an equidigital number, since it uses as much as digits as its factorization.

211663 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 211663 is about 460.0684731646. The cubic root of 211663 is about 59.5957078422.

Adding to 211663 its reverse (366112), we get a palindrome (577775).

Subtracting 211663 from its reverse (366112), we obtain a square (154449 = 393²).

The spelling of 211663 in words is "two hundred eleven thousand, six hundred sixty-three".