6978778 has 4 divisors (see below), whose sum is σ = 10468170. Its totient is φ = 3489388.

The previous prime is 6978761. The next prime is 6978779. The reversal of 6978778 is 8778796.

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., 6796449 + 182329 = 2607^2 + 427^2 .

It is not an unprimeable number, because it can be changed into a prime (6978779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1744693 + ... + 1744696.

Almost surely, 2^6978778 is an apocalyptic number.

6978778 is a deficient number, since it is larger than the sum of its proper divisors (3489392).

6978778 is a wasteful number, since it uses less digits than its factorization.

6978778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3489391.

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

The square root of 6978778 is about 2641.7376856910. The cubic root of 6978778 is about 191.0996072287.

The spelling of 6978778 in words is "six million, nine hundred seventy-eight thousand, seven hundred seventy-eight".