21334021 has 4 divisors (see below), whose sum is σ = 21395500. Its totient is φ = 21272544.

The previous prime is 21334007. The next prime is 21334039. The reversal of 21334021 is 12043312.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7562500 + 13771521 = 2750^2 + 3711^2 .

It is a cyclic number.

It is not a de Polignac number, because 21334021 - 2⁹ = 21333509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21333986 and 21334004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21334721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30216 + ... + 30913.

It is an arithmetic number, because the mean of its divisors is an integer number (5348875).

Almost surely, 2^21334021 is an apocalyptic number.

It is an amenable number.

21334021 is a deficient number, since it is larger than the sum of its proper divisors (61479).

21334021 is an equidigital number, since it uses as much as digits as its factorization.

21334021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61478.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 21334021 is about 4618.8765950175. The cubic root of 21334021 is about 277.3474897172.

Adding to 21334021 its reverse (12043312), we get a palindrome (33377333).

The spelling of 21334021 in words is "twenty-one million, three hundred thirty-four thousand, twenty-one".