1309223809 has 4 divisors (see below), whose sum is σ = 1311402820. Its totient is φ = 1307044800.

The previous prime is 1309223777. The next prime is 1309223831. The reversal of 1309223809 is 9083229031.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 684973584 + 624250225 = 26172^2 + 24985^2 .

It is a cyclic number.

It is not a de Polignac number, because 1309223809 - 2⁵ = 1309223777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1309227809) 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, 1088604 + ... + 1089805.

It is an arithmetic number, because the mean of its divisors is an integer number (327850705).

Almost surely, 2^1309223809 is an apocalyptic number.

It is an amenable number.

1309223809 is a deficient number, since it is larger than the sum of its proper divisors (2179011).

1309223809 is an equidigital number, since it uses as much as digits as its factorization.

1309223809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2179010.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 1309223809 is about 36183.1978824426. The cubic root of 1309223809 is about 1093.9680328372.

The spelling of 1309223809 in words is "one billion, three hundred nine million, two hundred twenty-three thousand, eight hundred nine".