1781340009 has 4 divisors (see below), whose sum is σ = 2375120016. Its totient is φ = 1187560004.

The previous prime is 1781339983. The next prime is 1781340031. The reversal of 1781340009 is 9000431871.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1781340009 - 2⁸ = 1781339753 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1781340049) 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, 296889999 + ... + 296890004.

It is an arithmetic number, because the mean of its divisors is an integer number (593780004).

Almost surely, 2^1781340009 is an apocalyptic number.

It is an amenable number.

1781340009 is a deficient number, since it is larger than the sum of its proper divisors (593780007).

1781340009 is an equidigital number, since it uses as much as digits as its factorization.

1781340009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593780006.

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 1781340009 is about 42205.9238614676. The cubic root of 1781340009 is about 1212.2223141896. Note that the first 3 decimals are identical.

The spelling of 1781340009 in words is "one billion, seven hundred eighty-one million, three hundred forty thousand, nine".