780845909 has 6 divisors (see below), whose sum is σ = 807927330. Its totient is φ = 753774896.

The previous prime is 780845899. The next prime is 780845917. The reversal of 780845909 is 909548087.

780845909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 334707025 + 446138884 = 18295^2 + 21122^2 .

It is a de Polignac number, because none of the positive numbers 2^k-780845909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (780845209) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 147887 + ... + 153075.

It is an arithmetic number, because the mean of its divisors is an integer number (134654555).

Almost surely, 2^780845909 is an apocalyptic number.

It is an amenable number.

780845909 is a deficient number, since it is larger than the sum of its proper divisors (27081421).

780845909 is an frugal number, since it uses more digits than its factorization.

780845909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10407 (or 5218 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 50.

The square root of 780845909 is about 27943.6201842209. The cubic root of 780845909 is about 920.8490543173.

The spelling of 780845909 in words is "seven hundred eighty million, eight hundred forty-five thousand, nine hundred nine".