6991078 has 4 divisors (see below), whose sum is σ = 10486620. Its totient is φ = 3495538.

The previous prime is 6991043. The next prime is 6991091. The reversal of 6991078 is 8701996.

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

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 6991078.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1747768 + ... + 1747771.

It is an arithmetic number, because the mean of its divisors is an integer number (2621655).

Almost surely, 2^6991078 is an apocalyptic number.

6991078 is a deficient number, since it is larger than the sum of its proper divisors (3495542).

6991078 is a wasteful number, since it uses less digits than its factorization.

6991078 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3495541.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 6991078 is about 2644.0646739443. The cubic root of 6991078 is about 191.2118114760.

The spelling of 6991078 in words is "six million, nine hundred ninety-one thousand, seventy-eight".