21234065 has 8 divisors (see below), whose sum is σ = 25767720. Its totient is φ = 16796032.

The previous prime is 21234049. The next prime is 21234067. The reversal of 21234065 is 56043212.

It can be written as a sum of positive squares in 4 ways, for example, as 37249 + 21196816 = 193^2 + 4604^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21234065 - 2⁴ = 21234049 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21234065.

It is not an unprimeable number, because it can be changed into a prime (21234067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23414 + ... + 24303.

It is an arithmetic number, because the mean of its divisors is an integer number (3220965).

Almost surely, 2^21234065 is an apocalyptic number.

It is an amenable number.

21234065 is a deficient number, since it is larger than the sum of its proper divisors (4533655).

21234065 is an equidigital number, since it uses as much as digits as its factorization.

21234065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47811.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 21234065 is about 4608.0435110793. The cubic root of 21234065 is about 276.9136606584.

Adding to 21234065 its reverse (56043212), we get a palindrome (77277277).

The spelling of 21234065 in words is "twenty-one million, two hundred thirty-four thousand, sixty-five".