6815978 has 8 divisors (see below), whose sum is σ = 11010468. Its totient is φ = 3145824.

The previous prime is 6815971. The next prime is 6816011. The reversal of 6815978 is 8795186.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6568969 + 247009 = 2563^2 + 497^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6815971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131051 + ... + 131102.

Almost surely, 2^6815978 is an apocalyptic number.

6815978 is a deficient number, since it is larger than the sum of its proper divisors (4194490).

6815978 is a wasteful number, since it uses less digits than its factorization.

6815978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262168.

The product of its digits is 120960, while the sum is 44.

The square root of 6815978 is about 2610.7428061761. The cubic root of 6815978 is about 189.6019181502.

The spelling of 6815978 in words is "six million, eight hundred fifteen thousand, nine hundred seventy-eight".