31481 has 2 divisors, whose sum is σ = 31482. Its totient is φ = 31480.

The previous prime is 31477. The next prime is 31489. The reversal of 31481 is 18413.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19600 + 11881 = 140^2 + 109^2 .

It is an emirp because it is prime and its reverse (18413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31481 - 2² = 31477 is a prime.

It is a super-2 number, since 2×31481² = 1982106722, which contains 22 as substring.

It is a Chen prime.

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 31481.

It is not a weakly prime, because it can be changed into another prime (31489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15740 + 15741.

It is an arithmetic number, because the mean of its divisors is an integer number (15741).

2³¹⁴⁸¹ is an apocalyptic number.

It is an amenable number.

31481 is a deficient number, since it is larger than the sum of its proper divisors (1).

31481 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 13 representation: 31481 = (11438)₁₃.

31481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 17.

The square root of 31481 is about 177.4288589830. The cubic root of 31481 is about 31.5754469317.

Adding to 31481 its reverse (18413), we get a palindrome (49894).

It can be divided in two parts, 31 and 481, that added together give a 9-th power (512 = 2⁹).

The spelling of 31481 in words is "thirty-one thousand, four hundred eighty-one".