6739991 has 4 divisors (see below), whose sum is σ = 6769152. Its totient is φ = 6710832.

The previous prime is 6739987. The next prime is 6740021. The reversal of 6739991 is 1999376.

It is a happy number.

6739991 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 6739991 - 2² = 6739987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6739921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14231 + ... + 14696.

It is an arithmetic number, because the mean of its divisors is an integer number (1692288).

Almost surely, 2^6739991 is an apocalyptic number.

6739991 is a deficient number, since it is larger than the sum of its proper divisors (29161).

6739991 is a wasteful number, since it uses less digits than its factorization.

6739991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29160.

The product of its digits is 91854, while the sum is 44.

The square root of 6739991 is about 2596.1492638136. The cubic root of 6739991 is about 188.8946997956.

The spelling of 6739991 in words is "six million, seven hundred thirty-nine thousand, nine hundred ninety-one".