561116809 has 12 divisors (see below), whose sum is σ = 643583808. Its totient is φ = 487925240.

The previous prime is 561116789. The next prime is 561116867. The reversal of 561116809 is 908611165.

561116809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 561116809 - 2¹¹ = 561114761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561116869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98029 + ... + 103594.

It is an arithmetic number, because the mean of its divisors is an integer number (53631984).

Almost surely, 2^561116809 is an apocalyptic number.

It is an amenable number.

561116809 is a deficient number, since it is larger than the sum of its proper divisors (82466999).

561116809 is a wasteful number, since it uses less digits than its factorization.

561116809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201668 (or 201657 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 561116809 is about 23687.9042762335. The cubic root of 561116809 is about 824.8046352216.

It can be divided in two parts, 561 and 116809, that added together give a triangular number (117370 = T₄₈₄).

The spelling of 561116809 in words is "five hundred sixty-one million, one hundred sixteen thousand, eight hundred nine".