6721739 has 2 divisors, whose sum is σ = 6721740. Its totient is φ = 6721738.

The previous prime is 6721733. The next prime is 6721747. The reversal of 6721739 is 9371276.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6721739 - 2⁴ = 6721723 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6721699 and 6721708.

It is not a weakly prime, because it can be changed into another prime (6721733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3360869 + 3360870.

It is an arithmetic number, because the mean of its divisors is an integer number (3360870).

Almost surely, 2^6721739 is an apocalyptic number.

6721739 is a deficient number, since it is larger than the sum of its proper divisors (1).

6721739 is an equidigital number, since it uses as much as digits as its factorization.

6721739 is an odious number, because the sum of its binary digits is odd.

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

The square root of 6721739 is about 2592.6316745732. The cubic root of 6721739 is about 188.7240357251.

The spelling of 6721739 in words is "six million, seven hundred twenty-one thousand, seven hundred thirty-nine".