6778987 has 4 divisors (see below), whose sum is σ = 6997696. Its totient is φ = 6560280.

The previous prime is 6778973. The next prime is 6779023. The reversal of 6778987 is 7898776.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 6778987 - 2¹⁵ = 6746219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6778927) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 109308 + ... + 109369.

It is an arithmetic number, because the mean of its divisors is an integer number (1749424).

Almost surely, 2^6778987 is an apocalyptic number.

6778987 is a deficient number, since it is larger than the sum of its proper divisors (218709).

6778987 is a wasteful number, since it uses less digits than its factorization.

6778987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218708.

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

The square root of 6778987 is about 2603.6487858388. The cubic root of 6778987 is about 189.2582995371.

It can be divided in two parts, 67789 and 87, that added together give a palindrome (67876).

The spelling of 6778987 in words is "six million, seven hundred seventy-eight thousand, nine hundred eighty-seven".