31723 has 2 divisors, whose sum is σ = 31724. Its totient is φ = 31722.

The previous prime is 31721. The next prime is 31727. The reversal of 31723 is 32713.

It is a weak prime.

It is an emirp because it is prime and its reverse (32713) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31723 - 2¹ = 31721 is a prime.

Together with 31721, it forms a pair of twin primes.

31723 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 31697 and 31706.

It is not a weakly prime, because it can be changed into another prime (31721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15861 + 15862.

It is an arithmetic number, because the mean of its divisors is an integer number (15862).

2³¹⁷²³ is an apocalyptic number.

31723 is a deficient number, since it is larger than the sum of its proper divisors (1).

31723 is an equidigital number, since it uses as much as digits as its factorization.

31723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 126, while the sum is 16.

The square root of 31723 is about 178.1095168709. The cubic root of 31723 is about 31.6561491696.

Subtracting 31723 from its reverse (32713), we obtain a triangular number (990 = T₄₄).

The spelling of 31723 in words is "thirty-one thousand, seven hundred twenty-three".