6778638 has 24 divisors (see below), whose sum is σ = 14742000. Its totient is φ = 2251104.

The previous prime is 6778637. The next prime is 6778643. The reversal of 6778638 is 8368776.

6778638 is a `hidden beast` number, since 6 + 7 + 7 + 8 + 638 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 6778593 and 6778602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6778637) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5938 + ... + 6986.

It is an arithmetic number, because the mean of its divisors is an integer number (614250).

Almost surely, 2^6778638 is an apocalyptic number.

6778638 is an abundant number, since it is smaller than the sum of its proper divisors (7963362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6778638 is a wasteful number, since it uses less digits than its factorization.

6778638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1416 (or 1413 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 6778638 is about 2603.5817636479. The cubic root of 6778638 is about 189.2550516437.

The spelling of 6778638 in words is "six million, seven hundred seventy-eight thousand, six hundred thirty-eight".