31290 has 32 divisors (see below), whose sum is σ = 86400. Its totient is φ = 7104.

The previous prime is 31277. The next prime is 31307. The reversal of 31290 is 9213.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a nialpdrome in base 15.

It is a congruent number.

It is an unprimeable number.

31290 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 15 ways as a sum of consecutive naturals, for example, 136 + ... + 284.

It is an arithmetic number, because the mean of its divisors is an integer number (2700).

2³¹²⁹⁰ is an apocalyptic number.

31290 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43200).

31290 is an abundant number, since it is smaller than the sum of its proper divisors (55110).

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

31290 is a wasteful number, since it uses less digits than its factorization.

31290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 31290 is about 176.8897962009. The cubic root of 31290 is about 31.5114596753.

The spelling of 31290 in words is "thirty-one thousand, two hundred ninety".