6887978 has 4 divisors (see below), whose sum is σ = 10331970. Its totient is φ = 3443988.

The previous prime is 6887953. The next prime is 6888019. The reversal of 6887978 is 8797886.

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., 4507129 + 2380849 = 2123^2 + 1543^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1721993 + ... + 1721996.

Almost surely, 2^6887978 is an apocalyptic number.

6887978 is a deficient number, since it is larger than the sum of its proper divisors (3443992).

6887978 is a wasteful number, since it uses less digits than its factorization.

6887978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3443991.

The product of its digits is 1354752, while the sum is 53.

The square root of 6887978 is about 2624.4957610939. The cubic root of 6887978 is about 190.2671956291.

The spelling of 6887978 in words is "six million, eight hundred eighty-seven thousand, nine hundred seventy-eight".