139031 has 4 divisors (see below), whose sum is σ = 142464. Its totient is φ = 135600.

The previous prime is 139021. The next prime is 139033. The reversal of 139031 is 130931.

139031 = T₆₁ + T₆₂ + ... + T₁₀₁.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130931 = 311 ⋅421.

It is a cyclic number.

It is not a de Polignac number, because 139031 - 2⁶ = 138967 is a prime.

It is a super-2 number, since 2×139031² = 38659237922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139031.

It is not an unprimeable number, because it can be changed into a prime (139033) 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, 1655 + ... + 1736.

It is an arithmetic number, because the mean of its divisors is an integer number (35616).

2¹³⁹⁰³¹ is an apocalyptic number.

139031 is a deficient number, since it is larger than the sum of its proper divisors (3433).

139031 is an equidigital number, since it uses as much as digits as its factorization.

139031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3432.

The product of its (nonzero) digits is 81, while the sum is 17.

The square root of 139031 is about 372.8686095664. The cubic root of 139031 is about 51.8048653023.

Adding to 139031 its reverse (130931), we get a palindrome (269962).

Subtracting from 139031 its reverse (130931), we obtain a square (8100 = 90²).

The spelling of 139031 in words is "one hundred thirty-nine thousand, thirty-one".