21816093 has 16 divisors (see below), whose sum is σ = 32056640. Its totient is φ = 13112064.

The previous prime is 21816089. The next prime is 21816103. The reversal of 21816093 is 39061812.

It is not a de Polignac number, because 21816093 - 2² = 21816089 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21816093.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21816293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4828 + ... + 8181.

It is an arithmetic number, because the mean of its divisors is an integer number (2003540).

Almost surely, 2^21816093 is an apocalyptic number.

It is an amenable number.

21816093 is a deficient number, since it is larger than the sum of its proper divisors (10240547).

21816093 is a wasteful number, since it uses less digits than its factorization.

21816093 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13068.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 21816093 is about 4670.7700649893. The cubic root of 21816093 is about 279.4209675174.

The spelling of 21816093 in words is "twenty-one million, eight hundred sixteen thousand, ninety-three".