6721839 has 16 divisors (see below), whose sum is σ = 10483200. Its totient is φ = 4245048.

The previous prime is 6721789. The next prime is 6721843. The reversal of 6721839 is 9381276.

It is not a de Polignac number, because 6721839 - 2⁷ = 6721711 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721849) 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, 6039 + ... + 7064.

It is an arithmetic number, because the mean of its divisors is an integer number (655200).

Almost surely, 2^6721839 is an apocalyptic number.

6721839 is a deficient number, since it is larger than the sum of its proper divisors (3761361).

6721839 is a wasteful number, since it uses less digits than its factorization.

6721839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13131 (or 13125 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 6721839 is about 2592.6509599250. The cubic root of 6721839 is about 188.7249716094.

The spelling of 6721839 in words is "six million, seven hundred twenty-one thousand, eight hundred thirty-nine".