21109327 has 2 divisors, whose sum is σ = 21109328. Its totient is φ = 21109326.

The previous prime is 21109321. The next prime is 21109367. The reversal of 21109327 is 72390112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21109327 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21109321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10554663 + 10554664.

It is an arithmetic number, because the mean of its divisors is an integer number (10554664).

Almost surely, 2^21109327 is an apocalyptic number.

21109327 is a deficient number, since it is larger than the sum of its proper divisors (1).

21109327 is an equidigital number, since it uses as much as digits as its factorization.

21109327 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21109327 is about 4594.4887637255. The cubic root of 21109327 is about 276.3703588882.

Adding to 21109327 its reverse (72390112), we get a palindrome (93499439).

The spelling of 21109327 in words is "twenty-one million, one hundred nine thousand, three hundred twenty-seven".