31393 has 2 divisors, whose sum is σ = 31394. Its totient is φ = 31392.

The previous prime is 31391. The next prime is 31397. The reversal of 31393 is 39313.

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., 31329 + 64 = 177^2 + 8^2 .

It is an emirp because it is prime and its reverse (39313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31393 - 2¹ = 31391 is a prime.

Together with 31391, it forms a pair of twin primes.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 31393.

It is not a weakly prime, because it can be changed into another prime (31391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15696 + 15697.

It is an arithmetic number, because the mean of its divisors is an integer number (15697).

2³¹³⁹³ is an apocalyptic number.

It is an amenable number.

31393 is a deficient number, since it is larger than the sum of its proper divisors (1).

31393 is an equidigital number, since it uses as much as digits as its factorization.

31393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 243, while the sum is 19.

The square root of 31393 is about 177.1806987231. The cubic root of 31393 is about 31.5459981379.

It can be divided in two parts, 313 and 93, that added together give a triangular number (406 = T₂₈).

The spelling of 31393 in words is "thirty-one thousand, three hundred ninety-three".