31280 has 40 divisors (see below), whose sum is σ = 80352. Its totient is φ = 11264.

The previous prime is 31277. The next prime is 31307. The reversal of 31280 is 8213.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable 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 7 ways as a sum of consecutive naturals, for example, 1349 + ... + 1371.

2³¹²⁸⁰ 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 31280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40176).

31280 is an abundant number, since it is smaller than the sum of its proper divisors (49072).

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

31280 is a wasteful number, since it uses less digits than its factorization.

31280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 31280 is about 176.8615277555. The cubic root of 31280 is about 31.5081023921.

Adding to 31280 its reverse (8213), we get a palindrome (39493).

The spelling of 31280 in words is "thirty-one thousand, two hundred eighty".