It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1343 = 17 ⋅79.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-3431 is a prime.
It is a Duffinian number.
It is a congruent number.
3431 is an equidigital number, since it uses as much as digits as its factorization.
3431 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 120.
The square root of 3431 is about 58.5747385824. The cubic root of 3431 is about 15.0825082896.
Adding to 3431 its reverse (1343), we get a palindrome (4774).
The spelling of 3431 in words is "three thousand, four hundred thirty-one".