561533817600 has 864 divisors, whose sum is σ = 2375389632000. Its totient is φ = 127143198720.

The previous prime is 561533817557. The next prime is 561533817601. The reversal of 561533817600 is 6718335165.

561533817600 is a `hidden beast` number, since 5 + 6 + 1 + 5 + 3 + 38 + 1 + 7 + 600 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (561533817601) 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 95 ways as a sum of consecutive naturals, for example, 131844271 + ... + 131848529.

Almost surely, 2^561533817600 is an apocalyptic number.

561533817600 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561533817600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1187694816000).

561533817600 is an abundant number, since it is smaller than the sum of its proper divisors (1813855814400).

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

561533817600 is a wasteful number, since it uses less digits than its factorization.

561533817600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4410 (or 4385 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 561533817600 in words is "five hundred sixty-one billion, five hundred thirty-three million, eight hundred seventeen thousand, six hundred".