561778776 has 192 divisors, whose sum is σ = 1782144000. Its totient is φ = 158319360.

The previous prime is 561778759. The next prime is 561778799. The reversal of 561778776 is 677877165.

561778776 is a `hidden beast` number, since 561 + 7 + 7 + 8 + 7 + 76 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 550795 + ... + 551813.

It is an arithmetic number, because the mean of its divisors is an integer number (9282000).

Almost surely, 2^561778776 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 561778776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (891072000).

561778776 is an abundant number, since it is smaller than the sum of its proper divisors (1220365224).

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

561778776 is a wasteful number, since it uses less digits than its factorization.

561778776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1094 (or 1087 counting only the distinct ones).

The product of its digits is 3457440, while the sum is 54.

The square root of 561778776 is about 23701.8728373941. The cubic root of 561778776 is about 825.1288570077.

The spelling of 561778776 in words is "five hundred sixty-one million, seven hundred seventy-eight thousand, seven hundred seventy-six".