6431 has 4 divisors (see below), whose sum is σ = 6600. Its totient is φ = 6264.

The previous prime is 6427. The next prime is 6449. The reversal of 6431 is 1346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1346 = 2 ⋅673.

It is a cyclic number.

It is not a de Polignac number, because 6431 - 2² = 6427 is a prime.

It is a super-2 number, since 2×6431² = 82715522, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5 + ... + 113.

It is an arithmetic number, because the mean of its divisors is an integer number (1650).

2⁶⁴³¹ is an apocalyptic number.

6431 is a deficient number, since it is larger than the sum of its proper divisors (169).

6431 is a wasteful number, since it uses less digits than its factorization.

6431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168.

The product of its digits is 72, while the sum is 14.

The square root of 6431 is about 80.1935159474. The cubic root of 6431 is about 18.5962839919.

Adding to 6431 its reverse (1346), we get a palindrome (7777).

The spelling of 6431 in words is "six thousand, four hundred thirty-one".