21847865188899 has 16 divisors (see below), whose sum is σ = 30664050934400. Its totient is φ = 13798480476096.

The previous prime is 21847865188871. The next prime is 21847865188907. The reversal of 21847865188899 is 99888156874812.

It is a Cunningham number, because it is equal to 4674170²-1.

It is not a de Polignac number, because 21847865188899 - 2⁴⁰ = 20748353561123 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21847865186899) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2337087 + ... + 7011255.

It is an arithmetic number, because the mean of its divisors is an integer number (1916503183400).

Almost surely, 2^{21847865188899} is an apocalyptic number.

21847865188899 is a deficient number, since it is larger than the sum of its proper divisors (8816185745501).

21847865188899 is a wasteful number, since it uses less digits than its factorization.

21847865188899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4756194.

The product of its digits is 4459069440, while the sum is 84.

The spelling of 21847865188899 in words is "twenty-one trillion, eight hundred forty-seven billion, eight hundred sixty-five million, one hundred eighty-eight thousand, eight hundred ninety-nine".