138031 has 4 divisors (see below), whose sum is σ = 139552. Its totient is φ = 136512.

The previous prime is 138007. The next prime is 138041. The reversal of 138031 is 130831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130831 = 41 ⋅3191.

It is a cyclic number.

It is not a de Polignac number, because 138031 - 2⁵ = 137999 is a prime.

It is a super-2 number, since 2×138031² = 38105113922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 137996 and 138014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138041) 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, 615 + ... + 808.

It is an arithmetic number, because the mean of its divisors is an integer number (34888).

2¹³⁸⁰³¹ is an apocalyptic number.

138031 is the 215-th hex number.

138031 is a deficient number, since it is larger than the sum of its proper divisors (1521).

138031 is an equidigital number, since it uses as much as digits as its factorization.

138031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 138031 is about 371.5252346746. The cubic root of 138031 is about 51.6803617297.

Adding to 138031 its reverse (130831), we get a palindrome (268862).

The spelling of 138031 in words is "one hundred thirty-eight thousand, thirty-one".