6381 has 6 divisors (see below), whose sum is σ = 9230. Its totient is φ = 4248.

The previous prime is 6379. The next prime is 6389. The reversal of 6381 is 1836.

It can be written as a sum of positive squares in only one way, i.e., 4356 + 2025 = 66^2 + 45^2 .

It is not a de Polignac number, because 6381 - 2¹ = 6379 is a prime.

It is a super-2 number, since 2×6381² = 81434322, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

6381 is a modest number, since divided by 81 gives 63 as remainder.

It is a Curzon number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6389) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 346 + ... + 363.

2⁶³⁸¹ is an apocalyptic number.

It is an amenable number.

6381 is a deficient number, since it is larger than the sum of its proper divisors (2849).

6381 is a wasteful number, since it uses less digits than its factorization.

6381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 712 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 6381 is about 79.8811617342. The cubic root of 6381 is about 18.5479641670.

It can be divided in two parts, 63 and 81, that added together give a square (144 = 12²).

The spelling of 6381 in words is "six thousand, three hundred eighty-one".