709740809 has 4 divisors (see below), whose sum is σ = 734214660. Its totient is φ = 685266960.

The previous prime is 709740797. The next prime is 709740817. The reversal of 709740809 is 908047907.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 908047907 = 13 ⋅69849839.

It can be written as a sum of positive squares in 2 ways, for example, as 567773584 + 141967225 = 23828^2 + 11915^2 .

It is a cyclic number.

It is not a de Polignac number, because 709740809 - 2²⁰ = 708692233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 709740809.

It is not an unprimeable number, because it can be changed into a prime (709746809) 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 3 ways as a sum of consecutive naturals, for example, 12236882 + ... + 12236939.

It is an arithmetic number, because the mean of its divisors is an integer number (183553665).

Almost surely, 2^709740809 is an apocalyptic number.

It is an amenable number.

709740809 is a deficient number, since it is larger than the sum of its proper divisors (24473851).

709740809 is a wasteful number, since it uses less digits than its factorization.

709740809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24473850.

The product of its (nonzero) digits is 127008, while the sum is 44.

The square root of 709740809 is about 26640.9611125425. The cubic root of 709740809 is about 892.0035697505.

The spelling of 709740809 in words is "seven hundred nine million, seven hundred forty thousand, eight hundred nine".