31880 has 16 divisors (see below), whose sum is σ = 71820. Its totient is φ = 12736.

The previous prime is 31873. The next prime is 31883. The reversal of 31880 is 8813.

It can be written as a sum of positive squares in 2 ways, for example, as 31684 + 196 = 178^2 + 14^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (31883) by changing a digit.

31880 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359 + ... + 438.

2³¹⁸⁸⁰ is an apocalyptic number.

It is an amenable number.

31880 is an abundant number, since it is smaller than the sum of its proper divisors (39940).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35910).

31880 is a wasteful number, since it uses less digits than its factorization.

31880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808 (or 804 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 31880 is about 178.5497129653. The cubic root of 31880 is about 31.7082863032.

The spelling of 31880 in words is "thirty-one thousand, eight hundred eighty".