31261 has 4 divisors (see below), whose sum is σ = 32032. Its totient is φ = 30492.

The previous prime is 31259. The next prime is 31267. The reversal of 31261 is 16213.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16213 = 31 ⋅523.

It is a cyclic number.

It is not a de Polignac number, because 31261 - 2¹ = 31259 is a prime.

It is a Duffinian number.

31261 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31267) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 321 + ... + 406.

It is an arithmetic number, because the mean of its divisors is an integer number (8008).

2³¹²⁶¹ is an apocalyptic number.

It is an amenable number.

31261 is a deficient number, since it is larger than the sum of its proper divisors (771).

31261 is an equidigital number, since it uses as much as digits as its factorization.

31261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770.

The product of its digits is 36, while the sum is 13.

The square root of 31261 is about 176.8078052576. The cubic root of 31261 is about 31.5017215822.

Adding to 31261 its reverse (16213), we get a palindrome (47474).

It can be divided in two parts, 312 and 61, that added together give a palindrome (373).

The spelling of 31261 in words is "thirty-one thousand, two hundred sixty-one".