991284411863 has 4 divisors (see below), whose sum is σ = 991316264928. Its totient is φ = 991252558800.

The previous prime is 991284411769. The next prime is 991284411883. The reversal of 991284411863 is 368114482199.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 368114482199 = 89051 ⋅4133749.

It is a cyclic number.

It is not a de Polignac number, because 991284411863 - 2³⁰ = 990210670039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 991284411799 and 991284411808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991284411883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15879806 + ... + 15942107.

It is an arithmetic number, because the mean of its divisors is an integer number (247829066232).

Almost surely, 2^991284411863 is an apocalyptic number.

991284411863 is a deficient number, since it is larger than the sum of its proper divisors (31853065).

991284411863 is a wasteful number, since it uses less digits than its factorization.

991284411863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31853064.

The product of its digits is 2985984, while the sum is 56.

The spelling of 991284411863 in words is "nine hundred ninety-one billion, two hundred eighty-four million, four hundred eleven thousand, eight hundred sixty-three".