21221303 has 2 divisors, whose sum is σ = 21221304. Its totient is φ = 21221302.

The previous prime is 21221293. The next prime is 21221339. The reversal of 21221303 is 30312212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221303 - 2⁸ = 21221047 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21221353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610651 + 10610652.

It is an arithmetic number, because the mean of its divisors is an integer number (10610652).

Almost surely, 2^21221303 is an apocalyptic number.

21221303 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221303 is an equidigital number, since it uses as much as digits as its factorization.

21221303 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21221303 is about 4606.6585504029. The cubic root of 21221303 is about 276.8581730827.

Adding to 21221303 its reverse (30312212), we get a palindrome (51533515).

Subtracting 21221303 from its reverse (30312212), we obtain a palindrome (9090909).

The spelling of 21221303 in words is "twenty-one million, two hundred twenty-one thousand, three hundred three".