138819 has 4 divisors (see below), whose sum is σ = 185096. Its totient is φ = 92544.

The previous prime is 138799. The next prime is 138821. The reversal of 138819 is 918831.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 138819 - 2⁸ = 138563 is a prime.

It is a super-2 number, since 2×138819² = 38541429522, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23134 + ... + 23139.

It is an arithmetic number, because the mean of its divisors is an integer number (46274).

2¹³⁸⁸¹⁹ is an apocalyptic number.

138819 is a deficient number, since it is larger than the sum of its proper divisors (46277).

138819 is an equidigital number, since it uses as much as digits as its factorization.

138819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46276.

The product of its digits is 1728, while the sum is 30.

The square root of 138819 is about 372.5842186674. The cubic root of 138819 is about 51.7785205341.

The spelling of 138819 in words is "one hundred thirty-eight thousand, eight hundred nineteen".