21115534099 has 4 divisors (see below), whose sum is σ = 23035128120. Its totient is φ = 19195940080.

The previous prime is 21115534061. The next prime is 21115534109. The reversal of 21115534099 is 99043551112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21115534099 - 2¹¹ = 21115532051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21115534019) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 959796994 + ... + 959797015.

It is an arithmetic number, because the mean of its divisors is an integer number (5758782030).

Almost surely, 2^21115534099 is an apocalyptic number.

21115534099 is a deficient number, since it is larger than the sum of its proper divisors (1919594021).

21115534099 is a wasteful number, since it uses less digits than its factorization.

21115534099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919594020.

The product of its (nonzero) digits is 48600, while the sum is 40.

The spelling of 21115534099 in words is "twenty-one billion, one hundred fifteen million, five hundred thirty-four thousand, ninety-nine".