31860 has 48 divisors (see below), whose sum is σ = 100800. Its totient is φ = 8352.

The previous prime is 31859. The next prime is 31873. The reversal of 31860 is 6813.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a plaindrome in 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 31860.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 511 + ... + 569.

It is an arithmetic number, because the mean of its divisors is an integer number (2100).

2³¹⁸⁶⁰ is an apocalyptic number.

31860 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50400).

31860 is an abundant number, since it is smaller than the sum of its proper divisors (68940).

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

31860 is a wasteful number, since it uses less digits than its factorization.

31860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 31860 is about 178.4936973677. The cubic root of 31860 is about 31.7016541578.

Adding to 31860 its sum of digits (18), we get a triangular number (31878 = T₂₅₂).

31860 divided by its sum of digits (18) gives a triangular number (1770 = T₅₉).

It can be divided in two parts, 318 and 60, that added together give a triangular number (378 = T₂₇).

The spelling of 31860 in words is "thirty-one thousand, eight hundred sixty".