6438 has 16 divisors (see below), whose sum is σ = 13680. Its totient is φ = 2016.

The previous prime is 6427. The next prime is 6449. The reversal of 6438 is 8346.

It is an interprime number because it is at equal distance from previous prime (6427) and next prime (6449).

It is a plaindrome in base 8 and base 14.

It is a nialpdrome in base 3 and base 9.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156 + ... + 192.

It is an arithmetic number, because the mean of its divisors is an integer number (855).

2⁶⁴³⁸ is an apocalyptic number.

6438 is an abundant number, since it is smaller than the sum of its proper divisors (7242).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6840).

6438 is a wasteful number, since it uses less digits than its factorization.

6438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71.

The product of its digits is 576, while the sum is 21.

The square root of 6438 is about 80.2371485037. The cubic root of 6438 is about 18.6030287587.

It can be divided in two parts, 6 and 438, that multiplied together give a triangular number (2628 = T₇₂).

The spelling of 6438 in words is "six thousand, four hundred thirty-eight".