6779991 has 16 divisors (see below), whose sum is σ = 9833184. Its totient is φ = 4137984.

The previous prime is 6779987. The next prime is 6779999. The reversal of 6779991 is 1999776.

It is not a de Polignac number, because 6779991 - 2² = 6779987 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6779991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6779999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91 + ... + 3683.

It is an arithmetic number, because the mean of its divisors is an integer number (614574).

Almost surely, 2^6779991 is an apocalyptic number.

6779991 is a deficient number, since it is larger than the sum of its proper divisors (3053193).

6779991 is a wasteful number, since it uses less digits than its factorization.

6779991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3650.

The product of its digits is 214326, while the sum is 48.

The square root of 6779991 is about 2603.8415850431. The cubic root of 6779991 is about 189.2676424253.

The spelling of 6779991 in words is "six million, seven hundred seventy-nine thousand, nine hundred ninety-one".