138818 has 8 divisors (see below), whose sum is σ = 215040. Its totient is φ = 67140.

The previous prime is 138799. The next prime is 138821. The reversal of 138818 is 818831.

138818 = 102² + 103² + ... + 113².

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138818.

It is an unprimeable 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 in 3 ways as a sum of consecutive naturals, for example, 1058 + ... + 1181.

It is an arithmetic number, because the mean of its divisors is an integer number (26880).

2¹³⁸⁸¹⁸ is an apocalyptic number.

138818 is a deficient number, since it is larger than the sum of its proper divisors (76222).

138818 is a wasteful number, since it uses less digits than its factorization.

138818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2272.

The product of its digits is 1536, while the sum is 29.

The square root of 138818 is about 372.5828766865. The cubic root of 138818 is about 51.7783962027.

The spelling of 138818 in words is "one hundred thirty-eight thousand, eight hundred eighteen".