809161945 has 4 divisors (see below), whose sum is σ = 970994340. Its totient is φ = 647329552.

The previous prime is 809161943. The next prime is 809161961. The reversal of 809161945 is 549161908.

809161945 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 499120281 + 310041664 = 22341^2 + 17608^2 .

It is a cyclic number.

It is not a de Polignac number, because 809161945 - 2¹ = 809161943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (809161943) 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, 80916190 + ... + 80916199.

It is an arithmetic number, because the mean of its divisors is an integer number (242748585).

Almost surely, 2^809161945 is an apocalyptic number.

It is an amenable number.

809161945 is a deficient number, since it is larger than the sum of its proper divisors (161832395).

809161945 is a wasteful number, since it uses less digits than its factorization.

809161945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161832394.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 809161945 is about 28445.7720056953. The cubic root of 809161945 is about 931.8481554492.

The spelling of 809161945 in words is "eight hundred nine million, one hundred sixty-one thousand, nine hundred forty-five".