861777845766 has 12 divisors (see below), whose sum is σ = 1867185332532. Its totient is φ = 287259281916.

The previous prime is 861777845711. The next prime is 861777845779. The reversal of 861777845766 is 667548777168.

861777845766 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×861777845766² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 861777845694 and 861777845703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 23938273476 + ... + 23938273511.

It is an arithmetic number, because the mean of its divisors is an integer number (155598777711).

Almost surely, 2^861777845766 is an apocalyptic number.

861777845766 is an abundant number, since it is smaller than the sum of its proper divisors (1005407486766).

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

861777845766 is a wasteful number, since it uses less digits than its factorization.

861777845766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47876546995 (or 47876546992 counting only the distinct ones).

The product of its digits is 663828480, while the sum is 72.

The spelling of 861777845766 in words is "eight hundred sixty-one billion, seven hundred seventy-seven million, eight hundred forty-five thousand, seven hundred sixty-six".