561993294644856 has 384 divisors, whose sum is σ = 1602437296824000. Its totient is φ = 184500675735552.

The previous prime is 561993294644759. The next prime is 561993294644861. The reversal of 561993294644856 is 658446492399165.

561993294644856 is a `hidden beast` number, since 5 + 6 + 1 + 9 + 9 + 32 + 94 + 6 + 448 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 53640664290 + ... + 53640674766.

Almost surely, 2^{561993294644856} 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 561993294644856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (801218648412000).

561993294644856 is an abundant number, since it is smaller than the sum of its proper divisors (1040444002179144).

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

561993294644856 is a wasteful number, since it uses less digits than its factorization.

561993294644856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11773 (or 11757 counting only the distinct ones).

The product of its digits is 12093235200, while the sum is 81.

The spelling of 561993294644856 in words is "five hundred sixty-one trillion, nine hundred ninety-three billion, two hundred ninety-four million, six hundred forty-four thousand, eight hundred fifty-six".