21383539905 has 128 divisors (see below), whose sum is σ = 44018150400. Its totient is φ = 8620867584.

The previous prime is 21383539889. The next prime is 21383539927. The reversal of 21383539905 is 50993538312.

It is not a de Polignac number, because 21383539905 - 2⁴ = 21383539889 is a prime.

It is a super-3 number, since 3×21383539905³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3836961 + ... + 3842529.

It is an arithmetic number, because the mean of its divisors is an integer number (343891800).

Almost surely, 2^21383539905 is an apocalyptic number.

It is an amenable number.

21383539905 is an abundant number, since it is smaller than the sum of its proper divisors (22634610495).

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

21383539905 is a wasteful number, since it uses less digits than its factorization.

21383539905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5723.

The product of its (nonzero) digits is 874800, while the sum is 48.

The spelling of 21383539905 in words is "twenty-one billion, three hundred eighty-three million, five hundred thirty-nine thousand, nine hundred five".