21222337 has 4 divisors (see below), whose sum is σ = 21232576. Its totient is φ = 21212100.

The previous prime is 21222293. The next prime is 21222343. The reversal of 21222337 is 73322212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21222337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21222347) 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, 789 + ... + 6562.

It is an arithmetic number, because the mean of its divisors is an integer number (5308144).

Almost surely, 2^21222337 is an apocalyptic number.

It is an amenable number.

21222337 is a deficient number, since it is larger than the sum of its proper divisors (10239).

21222337 is an equidigital number, since it uses as much as digits as its factorization.

21222337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10238.

The product of its digits is 1008, while the sum is 22.

The square root of 21222337 is about 4606.7707778877. The cubic root of 21222337 is about 276.8626696131.

Adding to 21222337 its reverse (73322212), we get a palindrome (94544549).

The spelling of 21222337 in words is "twenty-one million, two hundred twenty-two thousand, three hundred thirty-seven".