1816305409 has 8 divisors (see below), whose sum is σ = 1880433000. Its totient is φ = 1752277632.

The previous prime is 1816305397. The next prime is 1816305427. The reversal of 1816305409 is 9045036181.

It can be written as a sum of positive squares in 4 ways, for example, as 677040400 + 1139265009 = 26020^2 + 33753^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1816305409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1816305499) 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 7 ways as a sum of consecutive naturals, for example, 13087 + ... + 61675.

It is an arithmetic number, because the mean of its divisors is an integer number (235054125).

Almost surely, 2^1816305409 is an apocalyptic number.

It is an amenable number.

1816305409 is a deficient number, since it is larger than the sum of its proper divisors (64127591).

1816305409 is a wasteful number, since it uses less digits than its factorization.

1816305409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49907.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 1816305409 is about 42618.1347433226. The cubic root of 1816305409 is about 1220.1024300364.

The spelling of 1816305409 in words is "one billion, eight hundred sixteen million, three hundred five thousand, four hundred nine".