16663804263891 has 24 divisors (see below), whose sum is σ = 24193248805440. Its totient is φ = 11052296107776.

The previous prime is 16663804263871. The next prime is 16663804263919. The reversal of 16663804263891 is 19836240836661.

It is not a de Polignac number, because 16663804263891 - 2¹⁴ = 16663804247507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16663804263871) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39931371 + ... + 40346523.

It is an arithmetic number, because the mean of its divisors is an integer number (1008052033560).

Almost surely, 2^{16663804263891} is an apocalyptic number.

16663804263891 is a deficient number, since it is larger than the sum of its proper divisors (7529444541549).

16663804263891 is a wasteful number, since it uses less digits than its factorization.

16663804263891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437995 (or 437992 counting only the distinct ones).

The product of its (nonzero) digits is 53747712, while the sum is 63.

The spelling of 16663804263891 in words is "sixteen trillion, six hundred sixty-three billion, eight hundred four million, two hundred sixty-three thousand, eight hundred ninety-one".