1809393649 has 6 divisors (see below), whose sum is σ = 2104804914. Its totient is φ = 1550908800.

The previous prime is 1809393637. The next prime is 1809393653. The reversal of 1809393649 is 9463939081.

It can be written as a sum of positive squares in only one way, i.e., 1363972624 + 445421025 = 36932^2 + 21105^2 .

It is not a de Polignac number, because 1809393649 - 2²⁷ = 1675175921 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1809393596 and 1809393605.

It is not an unprimeable number, because it can be changed into a prime (1809394649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18463152 + ... + 18463249.

It is an arithmetic number, because the mean of its divisors is an integer number (350800819).

Almost surely, 2^1809393649 is an apocalyptic number.

It is an amenable number.

1809393649 is a deficient number, since it is larger than the sum of its proper divisors (295411265).

1809393649 is an equidigital number, since it uses as much as digits as its factorization.

1809393649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36926415 (or 36926408 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 52.

The square root of 1809393649 is about 42536.9680278226. The cubic root of 1809393649 is about 1218.5528053903.

The spelling of 1809393649 in words is "one billion, eight hundred nine million, three hundred ninety-three thousand, six hundred forty-nine".