218442 has 24 divisors (see below), whose sum is σ = 508896. Its totient is φ = 62328.

The previous prime is 218437. The next prime is 218447. The reversal of 218442 is 244812.

218442 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (218437) and next prime (218447).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (218447) by changing a digit.

218442 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78 + ... + 665.

It is an arithmetic number, because the mean of its divisors is an integer number (21204).

2²¹⁸⁴⁴² is an apocalyptic number.

218442 is an abundant number, since it is smaller than the sum of its proper divisors (290454).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218442 is a wasteful number, since it uses less digits than its factorization.

218442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762 (or 755 counting only the distinct ones).

The product of its digits is 512, while the sum is 21.

The square root of 218442 is about 467.3777915135. The cubic root of 218442 is about 60.2252643191.

The spelling of 218442 in words is "two hundred eighteen thousand, four hundred forty-two".