138811 has 4 divisors (see below), whose sum is σ = 140032. Its totient is φ = 137592.

The previous prime is 138799. The next prime is 138821. The reversal of 138811 is 118831.

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

It is a cyclic number.

It is not a de Polignac number, because 138811 - 2⁷ = 138683 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (138821) 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, 420 + ... + 673.

It is an arithmetic number, because the mean of its divisors is an integer number (35008).

2¹³⁸⁸¹¹ is an apocalyptic number.

138811 is a deficient number, since it is larger than the sum of its proper divisors (1221).

138811 is a wasteful number, since it uses less digits than its factorization.

138811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1220.

The product of its digits is 192, while the sum is 22.

The square root of 138811 is about 372.5734826850. The cubic root of 138811 is about 51.7775258668. Note that the first 3 decimals are identical.

It can be divided in two parts, 138 and 811, that added together give a palindrome (949).

The spelling of 138811 in words is "one hundred thirty-eight thousand, eight hundred eleven".