6921740809 has 9 divisors (see below), whose sum is σ = 6970080141. Its totient is φ = 6873736140.

The previous prime is 6921740803. The next prime is 6921740887. The reversal of 6921740809 is 9080471296.

The square root of 6921740809 is 83197.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 6921740809 - 2⁹ = 6921740297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6921740803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22546234 + ... + 22546540.

It is an arithmetic number, because the mean of its divisors is an integer number (774453349).

Almost surely, 2^6921740809 is an apocalyptic number.

6921740809 is the 83197-th square number.

6921740809 is the 41599-th centered octagonal number.

It is an amenable number.

6921740809 is a deficient number, since it is larger than the sum of its proper divisors (48339332).

6921740809 is an frugal number, since it uses more digits than its factorization.

6921740809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156 (or 578 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 46.

The cubic root of 6921740809 is about 1905.7756670226.

The spelling of 6921740809 in words is "six billion, nine hundred twenty-one million, seven hundred forty thousand, eight hundred nine".