218969 has 2 divisors, whose sum is σ = 218970. Its totient is φ = 218968.

The previous prime is 218963. The next prime is 218971. The reversal of 218969 is 969812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170569 + 48400 = 413^2 + 220^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218969 is a prime.

It is a super-2 number, since 2×218969² = 95894845922, which contains 22 as substring.

Together with 218971, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a plaindrome in base 13.

It is not a weakly prime, because it can be changed into another prime (218963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109484 + 109485.

It is an arithmetic number, because the mean of its divisors is an integer number (109485).

2²¹⁸⁹⁶⁹ is an apocalyptic number.

It is an amenable number.

218969 is a deficient number, since it is larger than the sum of its proper divisors (1).

218969 is an equidigital number, since it uses as much as digits as its factorization.

218969 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 218969 is about 467.9412356269. The cubic root of 218969 is about 60.2736573706.

The spelling of 218969 in words is "two hundred eighteen thousand, nine hundred sixty-nine".