561681120 has 576 divisors, whose sum is σ = 2432457216. Its totient is φ = 107089920.

The previous prime is 561681103. The next prime is 561681143. The reversal of 561681120 is 21186165.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

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 95 ways as a sum of consecutive naturals, for example, 3363277 + ... + 3363443.

It is an arithmetic number, because the mean of its divisors is an integer number (4223016).

Almost surely, 2^561681120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561681120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1216228608).

561681120 is an abundant number, since it is smaller than the sum of its proper divisors (1870776096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561681120 is a wasteful number, since it uses less digits than its factorization.

561681120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 561681120 is about 23699.8126574874. The cubic root of 561681120 is about 825.0810425437.

It can be divided in two parts, 5616 and 81120, that added together give a triangular number (86736 = T₄₁₆).

The spelling of 561681120 in words is "five hundred sixty-one million, six hundred eighty-one thousand, one hundred twenty".