155831 has 4 divisors (see below), whose sum is σ = 167832. Its totient is φ = 143832.

The previous prime is 155821. The next prime is 155833. The reversal of 155831 is 138551.

155831 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 138551 = 7 ⋅19793.

It is not a de Polignac number, because 155831 - 2¹⁰ = 154807 is a prime.

It is a super-2 number, since 2×155831² = 48566601122, 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 = 155797 and 155806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155833) 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, 5981 + ... + 6006.

It is an arithmetic number, because the mean of its divisors is an integer number (41958).

2¹⁵⁵⁸³¹ is an apocalyptic number.

155831 is a deficient number, since it is larger than the sum of its proper divisors (12001).

155831 is a wasteful number, since it uses less digits than its factorization.

155831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12000.

The product of its digits is 600, while the sum is 23.

The square root of 155831 is about 394.7543539975. The cubic root of 155831 is about 53.8126797180.

The spelling of 155831 in words is "one hundred fifty-five thousand, eight hundred thirty-one".