991918364463 has 48 divisors (see below), whose sum is σ = 1587049688224. Its totient is φ = 593125908480.

The previous prime is 991918364443. The next prime is 991918364497. The reversal of 991918364463 is 364463819199.

991918364463 is a `hidden beast` number, since 9 + 9 + 1 + 9 + 183 + 6 + 446 + 3 = 666.

It is not a de Polignac number, because 991918364463 - 2⁹ = 991918363951 is a prime.

It is a super-4 number, since 4×991918364463⁴ (a number of 49 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 991918364463.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991918364443) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 460203 + ... + 1481763.

Almost surely, 2^991918364463 is an apocalyptic number.

991918364463 is a deficient number, since it is larger than the sum of its proper divisors (595131323761).

991918364463 is a wasteful number, since it uses less digits than its factorization.

991918364463 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021816 (or 1021813 counting only the distinct ones).

The product of its digits is 30233088, while the sum is 63.

The spelling of 991918364463 in words is "nine hundred ninety-one billion, nine hundred eighteen million, three hundred sixty-four thousand, four hundred sixty-three".