561661059120 has 320 divisors, whose sum is σ = 2015755269120. Its totient is φ = 126721327104.

The previous prime is 561661059107. The next prime is 561661059133. The reversal of 561661059120 is 21950166165.

It is an interprime number because it is at equal distance from previous prime (561661059107) and next prime (561661059133).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 41191824 + ... + 41205456.

It is an arithmetic number, because the mean of its divisors is an integer number (6299235216).

Almost surely, 2^561661059120 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 561661059120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1007877634560).

561661059120 is an abundant number, since it is smaller than the sum of its proper divisors (1454094210000).

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

561661059120 is a wasteful number, since it uses less digits than its factorization.

561661059120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13972 (or 13966 counting only the distinct ones).

The product of its (nonzero) digits is 97200, while the sum is 42.

The spelling of 561661059120 in words is "five hundred sixty-one billion, six hundred sixty-one million, fifty-nine thousand, one hundred twenty".