991130777866612 has 6 divisors (see below), whose sum is σ = 1734478861266578. Its totient is φ = 495565388933304.

The previous prime is 991130777866591. The next prime is 991130777866763. The reversal of 991130777866612 is 216668777031199.

It can be written as a sum of positive squares in only one way, i.e., 632901114440676 + 358229663425936 = 25157526^2 + 18926956^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123891347233323 + ... + 123891347233330.

Almost surely, 2^{991130777866612} is an apocalyptic number.

It is an amenable number.

991130777866612 is a deficient number, since it is larger than the sum of its proper divisors (743348083399966).

991130777866612 is a wasteful number, since it uses less digits than its factorization.

991130777866612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247782694466657 (or 247782694466655 counting only the distinct ones).

The product of its (nonzero) digits is 288054144, while the sum is 73.

The spelling of 991130777866612 in words is "nine hundred ninety-one trillion, one hundred thirty billion, seven hundred seventy-seven million, eight hundred sixty-six thousand, six hundred twelve".