6815988 has 60 divisors (see below), whose sum is σ = 18074980. Its totient is φ = 2239488.

The previous prime is 6815971. The next prime is 6816011. The reversal of 6815988 is 8895186.

It can be written as a sum of positive squares in 2 ways, for example, as 3175524 + 3640464 = 1782^2 + 1908^2 .

It is a super-2 number, since 2×6815988² = 92915384832288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 35220 + ... + 35412.

Almost surely, 2^6815988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6815988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9037490).

6815988 is an abundant number, since it is smaller than the sum of its proper divisors (11258992).

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

6815988 is a wasteful number, since it uses less digits than its factorization.

6815988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 307 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 6815988 is about 2610.7447213391. The cubic root of 6815988 is about 189.6020108744.

The spelling of 6815988 in words is "six million, eight hundred fifteen thousand, nine hundred eighty-eight".