21089440115 has 4 divisors (see below), whose sum is σ = 25307328144. Its totient is φ = 16871552088.

The previous prime is 21089440109. The next prime is 21089440123. The reversal of 21089440115 is 51104498012.

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 21089440115 - 2⁸ = 21089439859 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2108944007 + ... + 2108944016.

It is an arithmetic number, because the mean of its divisors is an integer number (6326832036).

Almost surely, 2^21089440115 is an apocalyptic number.

21089440115 is a deficient number, since it is larger than the sum of its proper divisors (4217888029).

21089440115 is an equidigital number, since it uses as much as digits as its factorization.

21089440115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4217888028.

The product of its (nonzero) digits is 11520, while the sum is 35.

The spelling of 21089440115 in words is "twenty-one billion, eighty-nine million, four hundred forty thousand, one hundred fifteen".