218919 has 4 divisors (see below), whose sum is σ = 291896. Its totient is φ = 145944.

The previous prime is 218887. The next prime is 218923. The reversal of 218919 is 919812.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 218919 - 2⁵ = 218887 is a prime.

It is a super-2 number, since 2×218919² = 95851057122, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218969) 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 in 3 ways as a sum of consecutive naturals, for example, 36484 + ... + 36489.

It is an arithmetic number, because the mean of its divisors is an integer number (72974).

2²¹⁸⁹¹⁹ is an apocalyptic number.

218919 is a deficient number, since it is larger than the sum of its proper divisors (72977).

218919 is an equidigital number, since it uses as much as digits as its factorization.

218919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72976.

The product of its digits is 1296, while the sum is 30.

The square root of 218919 is about 467.8878070649. The cubic root of 218919 is about 60.2690693356.

The spelling of 218919 in words is "two hundred eighteen thousand, nine hundred nineteen".