218623 has 2 divisors, whose sum is σ = 218624. Its totient is φ = 218622.

The previous prime is 218611. The next prime is 218627. The reversal of 218623 is 326812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 218623 - 2⁵ = 218591 is a prime.

It is a super-2 number, since 2×218623² = 95592032258, which contains 22 as substring.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 218594 and 218603.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109311 + 109312.

It is an arithmetic number, because the mean of its divisors is an integer number (109312).

2²¹⁸⁶²³ is an apocalyptic number.

218623 is a deficient number, since it is larger than the sum of its proper divisors (1).

218623 is an equidigital number, since it uses as much as digits as its factorization.

218623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 22.

The square root of 218623 is about 467.5713849243. The cubic root of 218623 is about 60.2418938493.

It can be divided in two parts, 2186 and 23, that added together give a square (2209 = 47²).

The spelling of 218623 in words is "two hundred eighteen thousand, six hundred twenty-three".