31388 has 24 divisors (see below), whose sum is σ = 67200. Its totient is φ = 12528.

The previous prime is 31387. The next prime is 31391. The reversal of 31388 is 88313.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 503 + ... + 561.

It is an arithmetic number, because the mean of its divisors is an integer number (2800).

2³¹³⁸⁸ is an apocalyptic number.

31388 is a gapful number since it is divisible by the number (38) 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 31388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33600).

31388 is an abundant number, since it is smaller than the sum of its proper divisors (35812).

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

31388 is a wasteful number, since it uses less digits than its factorization.

31388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 87 counting only the distinct ones).

The product of its digits is 576, while the sum is 23.

The square root of 31388 is about 177.1665882722. The cubic root of 31388 is about 31.5443232595.

The spelling of 31388 in words is "thirty-one thousand, three hundred eighty-eight".