561785123 has 4 divisors (see below), whose sum is σ = 561964368. Its totient is φ = 561605880.

The previous prime is 561785117. The next prime is 561785137. The reversal of 561785123 is 321587165.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 561785123 - 2¹⁰ = 561784099 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561785183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84836 + ... + 91217.

It is an arithmetic number, because the mean of its divisors is an integer number (140491092).

Almost surely, 2^561785123 is an apocalyptic number.

561785123 is a deficient number, since it is larger than the sum of its proper divisors (179245).

561785123 is a wasteful number, since it uses less digits than its factorization.

561785123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179244.

The product of its digits is 50400, while the sum is 38.

The square root of 561785123 is about 23702.0067293890. The cubic root of 561785123 is about 825.1319644427.

The spelling of 561785123 in words is "five hundred sixty-one million, seven hundred eighty-five thousand, one hundred twenty-three".