138831 has 16 divisors (see below), whose sum is σ = 231168. Its totient is φ = 72000.

The previous prime is 138829. The next prime is 138841.

138831 = 93² + 94² + ... + 106².

138831 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 138831 - 2¹ = 138829 is a prime.

It is a super-2 number, since 2×138831² = 38548093122, which contains 22 as substring.

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 138831.

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 15 ways as a sum of consecutive naturals, for example, 70 + ... + 531.

It is an arithmetic number, because the mean of its divisors is an integer number (14448).

2¹³⁸⁸³¹ is an apocalyptic number.

138831 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138831 is a deficient number, since it is larger than the sum of its proper divisors (92337).

138831 is a wasteful number, since it uses less digits than its factorization.

138831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622.

The product of its digits is 576, while the sum is 24.

The square root of 138831 is about 372.6003220611. The cubic root of 138831 is about 51.7800124632.

It can be divided in two parts, 138 and 831, that added together give a palindrome (969).

The spelling of 138831 in words is "one hundred thirty-eight thousand, eight hundred thirty-one".