561116777781 has 16 divisors (see below), whose sum is σ = 855115618304. Its totient is φ = 320607960624.

The previous prime is 561116777773. The next prime is 561116777783. The reversal of 561116777781 is 187777611165.

It is not a de Polignac number, because 561116777781 - 2³ = 561116777773 is a prime.

It is a super-2 number, since 2×561116777781² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561116777783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1029001 + ... + 1476846.

It is an arithmetic number, because the mean of its divisors is an integer number (53444726144).

Almost surely, 2^561116777781 is an apocalyptic number.

It is an amenable number.

561116777781 is a deficient number, since it is larger than the sum of its proper divisors (293998840523).

561116777781 is a wasteful number, since it uses less digits than its factorization.

561116777781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2516520.

The product of its digits is 3457440, while the sum is 57.

The spelling of 561116777781 in words is "five hundred sixty-one billion, one hundred sixteen million, seven hundred seventy-seven thousand, seven hundred eighty-one".