21109367 has 2 divisors, whose sum is σ = 21109368. Its totient is φ = 21109366.

The previous prime is 21109327. The next prime is 21109369. The reversal of 21109367 is 76390112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21109367 - 2¹⁰ = 21108343 is a prime.

Together with 21109369, 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 (21109369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10554683 + 10554684.

It is an arithmetic number, because the mean of its divisors is an integer number (10554684).

Almost surely, 2^21109367 is an apocalyptic number.

21109367 is a deficient number, since it is larger than the sum of its proper divisors (1).

21109367 is an equidigital number, since it uses as much as digits as its factorization.

21109367 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 21109367 is about 4594.4931167649. The cubic root of 21109367 is about 276.3705334525.

Adding to 21109367 its reverse (76390112), we get a palindrome (97499479).

The spelling of 21109367 in words is "twenty-one million, one hundred nine thousand, three hundred sixty-seven".