561781785600 has 2376 divisors, whose sum is σ = 2580547438560. Its totient is φ = 120394874880.

The previous prime is 561781785599. The next prime is 561781785601. The reversal of 561781785600 is 6587187165.

561781785600 is a `hidden beast` number, since 5 + 6 + 1 + 7 + 8 + 1 + 78 + 560 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (561781785599) and next prime (561781785601).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (561781785601) by changing a digit.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 5791564752 + ... + 5791564848.

Almost surely, 2^561781785600 is an apocalyptic number.

561781785600 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 561781785600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1290273719280).

561781785600 is an abundant number, since it is smaller than the sum of its proper divisors (2018765652960).

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

561781785600 is a wasteful number, since it uses less digits than its factorization.

561781785600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 561781785600 in words is "five hundred sixty-one billion, seven hundred eighty-one million, seven hundred eighty-five thousand, six hundred".