21303671 has 2 divisors, whose sum is σ = 21303672. Its totient is φ = 21303670.

The previous prime is 21303649. The next prime is 21303673. The reversal of 21303671 is 17630312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21303671 is a prime.

It is a Sophie Germain prime.

Together with 21303673, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21303673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651835 + 10651836.

It is an arithmetic number, because the mean of its divisors is an integer number (10651836).

Almost surely, 2^21303671 is an apocalyptic number.

21303671 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303671 is an equidigital number, since it uses as much as digits as its factorization.

21303671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 21303671 is about 4615.5899947894. The cubic root of 21303671 is about 277.2159081606.

Adding to 21303671 its reverse (17630312), we get a palindrome (38933983).

The spelling of 21303671 in words is "twenty-one million, three hundred three thousand, six hundred seventy-one".