6615 has 24 divisors (see below), whose sum is σ = 13680. Its totient is φ = 3024.

The previous prime is 6607. The next prime is 6619. The reversal of 6615 is 5166.

Added to its reverse (5166) it gives a triangular number (11781 = T₁₅₃).

6615 is a `hidden beast` number, since 661 + 5 = 666.

It is not a de Polignac number, because 6615 - 2³ = 6607 is a prime.

Its product of digits (180) is a multiple of the sum of its prime divisors (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6619) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 942 + ... + 948.

It is an arithmetic number, because the mean of its divisors is an integer number (570).

2⁶⁶¹⁵ is an apocalyptic number.

6615 is an abundant number, since it is smaller than the sum of its proper divisors (7065).

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).

6615 is a wasteful number, since it uses less digits than its factorization.

6615 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28 (or 15 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 6615 is about 81.3326502704. The cubic root of 6615 is about 18.7719742370.

Adding to 6615 its reverse (5166), we get a triangular number (11781 = T₁₅₃).

It can be divided in two parts, 661 and 5, that added together give a palindrome (666).

The spelling of 6615 in words is "six thousand, six hundred fifteen".