6691878 has 24 divisors (see below), whose sum is σ = 14552928. Its totient is φ = 2222352.

The previous prime is 6691859. The next prime is 6691891. The reversal of 6691878 is 8781966.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6100 + ... + 7112.

It is an arithmetic number, because the mean of its divisors is an integer number (606372).

Almost surely, 2^6691878 is an apocalyptic number.

6691878 is an abundant number, since it is smaller than the sum of its proper divisors (7861050).

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

6691878 is a wasteful number, since it uses less digits than its factorization.

6691878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388 (or 1385 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 6691878 is about 2586.8664441753. The cubic root of 6691878 is about 188.4441550664. Note that the first 3 decimals are identical.

It can be divided in two parts, 6691 and 878, that added together give a square (7569 = 87²).

The spelling of 6691878 in words is "six million, six hundred ninety-one thousand, eight hundred seventy-eight".