991061143884 has 120 divisors (see below), whose sum is σ = 3116787618560. Its totient is φ = 268257140064.

The previous prime is 991061143879. The next prime is 991061143907. The reversal of 991061143884 is 488341160199.

991061143884 is a `hidden beast` number, since 9 + 9 + 10 + 611 + 4 + 3 + 8 + 8 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 991061143884.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11456272 + ... + 11542455.

Almost surely, 2^991061143884 is an apocalyptic number.

It is an amenable number.

991061143884 is an abundant number, since it is smaller than the sum of its proper divisors (2125726474676).

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

991061143884 is a wasteful number, since it uses less digits than its factorization.

991061143884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22998769 (or 22998758 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 54.

The spelling of 991061143884 in words is "nine hundred ninety-one billion, sixty-one million, one hundred forty-three thousand, eight hundred eighty-four".