138891 has 8 divisors (see below), whose sum is σ = 188224. Its totient is φ = 91080.

The previous prime is 138889. The next prime is 138893. The reversal of 138891 is 198831.

138891 is digitally balanced in base 2, because in such base 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 (138889) and next prime (138893).

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

It is not a de Polignac number, because 138891 - 2¹ = 138889 is a prime.

It is a Duffinian number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (138893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145 + ... + 546.

It is an arithmetic number, because the mean of its divisors is an integer number (23528).

2¹³⁸⁸⁹¹ is an apocalyptic number.

138891 is a deficient number, since it is larger than the sum of its proper divisors (49333).

138891 is an equidigital number, since it uses as much as digits as its factorization.

138891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761.

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

The square root of 138891 is about 372.6808285920. The cubic root of 138891 is about 51.7874708198.

The spelling of 138891 in words is "one hundred thirty-eight thousand, eight hundred ninety-one".