6778978 has 4 divisors (see below), whose sum is σ = 10168470. Its totient is φ = 3389488.

The previous prime is 6778973. The next prime is 6779023. The reversal of 6778978 is 8798776.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 6365529 + 413449 = 2523^2 + 643^2 .

It is not an unprimeable number, because it can be changed into a prime (6778973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1694743 + ... + 1694746.

Almost surely, 2^6778978 is an apocalyptic number.

6778978 is a deficient number, since it is larger than the sum of its proper divisors (3389492).

6778978 is a wasteful number, since it uses less digits than its factorization.

6778978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3389491.

The product of its digits is 1185408, while the sum is 52.

The square root of 6778978 is about 2603.6470574945. The cubic root of 6778978 is about 189.2582157819.

The spelling of 6778978 in words is "six million, seven hundred seventy-eight thousand, nine hundred seventy-eight".