218923 has 2 divisors, whose sum is σ = 218924. Its totient is φ = 218922.

The previous prime is 218887. The next prime is 218941. The reversal of 218923 is 329812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218923 - 2¹³ = 210731 is a prime.

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

It is equal to p₁₉₅₁₉ and since 218923 and 19519 have the same sum of digits, it is a Honaker prime.

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, 109461 + 109462.

It is an arithmetic number, because the mean of its divisors is an integer number (109462).

2²¹⁸⁹²³ is an apocalyptic number.

218923 is a deficient number, since it is larger than the sum of its proper divisors (1).

218923 is an equidigital number, since it uses as much as digits as its factorization.

218923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 218923 is about 467.8920815744. The cubic root of 218923 is about 60.2694364041.

Subtracting 218923 from its reverse (329812), we obtain a square (110889 = 333²).

The spelling of 218923 in words is "two hundred eighteen thousand, nine hundred twenty-three".