138218 has 4 divisors (see below), whose sum is σ = 207330. Its totient is φ = 69108.

The previous prime is 138209. The next prime is 138239. The reversal of 138218 is 812831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 812831 = 79 ⋅10289.

It can be written as a sum of positive squares in only one way, i.e., 113569 + 24649 = 337^2 + 157^2 .

It is a junction number, because it is equal to n+sod(n) for n = 138193 and 138202.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138218.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34553 + ... + 34556.

2¹³⁸²¹⁸ is an apocalyptic number.

138218 is a deficient number, since it is larger than the sum of its proper divisors (69112).

138218 is an equidigital number, since it uses as much as digits as its factorization.

138218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69111.

The product of its digits is 384, while the sum is 23.

The square root of 138218 is about 371.7768147693. The cubic root of 138218 is about 51.7036895007.

The spelling of 138218 in words is "one hundred thirty-eight thousand, two hundred eighteen".