218432 has 14 divisors (see below), whose sum is σ = 433578. Its totient is φ = 109184.

The previous prime is 218423. The next prime is 218437. The reversal of 218432 is 234812.

It can be written as a sum of positive squares in only one way, i.e., 215296 + 3136 = 464^2 + 56^2 .

It is a nialpdrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218437) by changing a digit.

218432 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1643 + ... + 1770.

2²¹⁸⁴³² is an apocalyptic number.

It is an amenable number.

218432 is a deficient number, since it is larger than the sum of its proper divisors (215146).

218432 is an equidigital number, since it uses as much as digits as its factorization.

218432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3425 (or 3415 counting only the distinct ones).

The product of its digits is 384, while the sum is 20.

The square root of 218432 is about 467.3670934073. The cubic root of 218432 is about 60.2243452928.

It can be divided in two parts, 2 and 18432, that multiplied together give a square (36864 = 192²).

The spelling of 218432 in words is "two hundred eighteen thousand, four hundred thirty-two".