6781978 has 16 divisors (see below), whose sum is σ = 11759040. Its totient is φ = 2873376.

The previous prime is 6781967. The next prime is 6782021. The reversal of 6781978 is 8791876.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1476 + ... + 3967.

It is an arithmetic number, because the mean of its divisors is an integer number (734940).

Almost surely, 2^6781978 is an apocalyptic number.

6781978 is a deficient number, since it is larger than the sum of its proper divisors (4977062).

6781978 is a wasteful number, since it uses less digits than its factorization.

6781978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5541.

The product of its digits is 169344, while the sum is 46.

The square root of 6781978 is about 2604.2231087217. The cubic root of 6781978 is about 189.2861300640.

The spelling of 6781978 in words is "six million, seven hundred eighty-one thousand, nine hundred seventy-eight".