31643 has 2 divisors, whose sum is σ = 31644. Its totient is φ = 31642.

The previous prime is 31627. The next prime is 31649. The reversal of 31643 is 34613.

It is a strong prime.

It is an emirp because it is prime and its reverse (34613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31643 - 2⁴ = 31627 is a prime.

It is a Chen prime.

It is a nialpdrome in base 14.

It is not a weakly prime, because it can be changed into another prime (31649) 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, 15821 + 15822.

It is an arithmetic number, because the mean of its divisors is an integer number (15822).

2³¹⁶⁴³ is an apocalyptic number.

31643 is a deficient number, since it is larger than the sum of its proper divisors (1).

31643 is an equidigital number, since it uses as much as digits as its factorization.

31643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 17.

The square root of 31643 is about 177.8847941787. The cubic root of 31643 is about 31.6295162979.

Subtracting from 31643 its sum of digits (17), we obtain a triangular number (31626 = T₂₅₁).

The spelling of 31643 in words is "thirty-one thousand, six hundred forty-three".