6739721 has 4 divisors (see below), whose sum is σ = 6745872. Its totient is φ = 6733572.

The previous prime is 6739709. The next prime is 6739723. The reversal of 6739721 is 1279376.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6739721 - 2¹⁸ = 6477577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6739723) 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, 935 + ... + 3788.

It is an arithmetic number, because the mean of its divisors is an integer number (1686468).

Almost surely, 2^6739721 is an apocalyptic number.

It is an amenable number.

6739721 is a deficient number, since it is larger than the sum of its proper divisors (6151).

6739721 is a wasteful number, since it uses less digits than its factorization.

6739721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6150.

The product of its digits is 15876, while the sum is 35.

The square root of 6739721 is about 2596.0972632011. The cubic root of 6739721 is about 188.8921774258.

The spelling of 6739721 in words is "six million, seven hundred thirty-nine thousand, seven hundred twenty-one".