31856 has 20 divisors (see below), whose sum is σ = 67704. Its totient is φ = 14400.

The previous prime is 31849. The next prime is 31859. The reversal of 31856 is 65813.

It is a plaindrome in base 13.

It is a nialpdrome in base 14.

It is a zygodrome in base 2 and base 13.

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 31856.

It is not an unprimeable number, because it can be changed into a prime (31859) by changing a digit.

31856 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86 + ... + 266.

2³¹⁸⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33852).

31856 is an abundant number, since it is smaller than the sum of its proper divisors (35848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31856 is a wasteful number, since it uses less digits than its factorization.

31856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 194 counting only the distinct ones).

The product of its digits is 720, while the sum is 23.

The square root of 31856 is about 178.4824921386. The cubic root of 31856 is about 31.7003273956.

It can be divided in two parts, 3185 and 6, that multiplied together give a triangular number (19110 = T₁₉₅).

The spelling of 31856 in words is "thirty-one thousand, eight hundred fifty-six".