21226165 has 8 divisors (see below), whose sum is σ = 26293248. Its totient is φ = 16433040.

The previous prime is 21226157. The next prime is 21226181. The reversal of 21226165 is 56162212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21226165 - 2³ = 21226157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 68317 + ... + 68626.

It is an arithmetic number, because the mean of its divisors is an integer number (3286656).

Almost surely, 2^21226165 is an apocalyptic number.

It is an amenable number.

21226165 is a deficient number, since it is larger than the sum of its proper divisors (5067083).

21226165 is a wasteful number, since it uses less digits than its factorization.

21226165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136979.

The product of its digits is 1440, while the sum is 25.

The square root of 21226165 is about 4607.1862345688. The cubic root of 21226165 is about 276.8793150715.

Adding to 21226165 its reverse (56162212), we get a palindrome (77388377).

The spelling of 21226165 in words is "twenty-one million, two hundred twenty-six thousand, one hundred sixty-five".