6390 has 24 divisors (see below), whose sum is σ = 16848. Its totient is φ = 1680.

The previous prime is 6389. The next prime is 6397. The reversal of 6390 is 936.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a plaindrome in base 11.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 6390.

It is not an unprimeable number, because it can be changed into a prime (6397) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55 + ... + 125.

It is an arithmetic number, because the mean of its divisors is an integer number (702).

2⁶³⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8424).

6390 is an abundant number, since it is smaller than the sum of its proper divisors (10458).

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

6390 is a wasteful number, since it uses less digits than its factorization.

6390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

The square root of 6390 is about 79.9374755668. The cubic root of 6390 is about 18.5566803169.

It can be divided in two parts, 63 and 90, that added together give a triangular number (153 = T₁₇).

The spelling of 6390 in words is "six thousand, three hundred ninety".