561680123 has 4 divisors (see below), whose sum is σ = 562530528. Its totient is φ = 560829720.

The previous prime is 561680111. The next prime is 561680137. The reversal of 561680123 is 321086165.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561680123 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 561680123.

It is not an unprimeable number, because it can be changed into a prime (561680183) 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, 424211 + ... + 425532.

It is an arithmetic number, because the mean of its divisors is an integer number (140632632).

Almost surely, 2^561680123 is an apocalyptic number.

561680123 is a deficient number, since it is larger than the sum of its proper divisors (850405).

561680123 is an equidigital number, since it uses as much as digits as its factorization.

561680123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 850404.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 561680123 is about 23699.7916235565. The cubic root of 561680123 is about 825.0805543626.

The spelling of 561680123 in words is "five hundred sixty-one million, six hundred eighty thousand, one hundred twenty-three".