561672778385 has 4 divisors (see below), whose sum is σ = 674007334068. Its totient is φ = 449338222704.

The previous prime is 561672778367. The next prime is 561672778427. The reversal of 561672778385 is 583877276165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 583877276165 = 5 ⋅116775455233.

It can be written as a sum of positive squares in 2 ways, for example, as 221362722064 + 340310056321 = 470492^2 + 583361^2 .

It is a cyclic number.

It is not a de Polignac number, because 561672778385 - 2¹⁰ = 561672777361 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56167277834 + ... + 56167277843.

It is an arithmetic number, because the mean of its divisors is an integer number (168501833517).

Almost surely, 2^561672778385 is an apocalyptic number.

It is an amenable number.

561672778385 is a deficient number, since it is larger than the sum of its proper divisors (112334555683).

561672778385 is a wasteful number, since it uses less digits than its factorization.

561672778385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112334555682.

The product of its digits is 118540800, while the sum is 65.

The spelling of 561672778385 in words is "five hundred sixty-one billion, six hundred seventy-two million, seven hundred seventy-eight thousand, three hundred eighty-five".