561661184 has 144 divisors (see below), whose sum is σ = 1353356928. Its totient is φ = 227598336.

The previous prime is 561661159. The next prime is 561661207. The reversal of 561661184 is 481166165.

It is a super-2 number, since 2×561661184² = 630926571224563712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2850974 + ... + 2851170.

It is an arithmetic number, because the mean of its divisors is an integer number (9398312).

Almost surely, 2^561661184 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 561661184, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (676678464).

561661184 is an abundant number, since it is smaller than the sum of its proper divisors (791695744).

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

561661184 is a wasteful number, since it uses less digits than its factorization.

561661184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300 (or 286 counting only the distinct ones).

The product of its digits is 34560, while the sum is 38.

The square root of 561661184 is about 23699.3920597133. The cubic root of 561661184 is about 825.0712807710.

The spelling of 561661184 in words is "five hundred sixty-one million, six hundred sixty-one thousand, one hundred eighty-four".