21368803 has 2 divisors, whose sum is σ = 21368804. Its totient is φ = 21368802.

The previous prime is 21368801. The next prime is 21368821. The reversal of 21368803 is 30886312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21368803 - 2¹ = 21368801 is a prime.

Together with 21368801, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21368801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10684401 + 10684402.

It is an arithmetic number, because the mean of its divisors is an integer number (10684402).

Almost surely, 2^21368803 is an apocalyptic number.

21368803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21368803 is an equidigital number, since it uses as much as digits as its factorization.

21368803 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 21368803 is about 4622.6402628801. The cubic root of 21368803 is about 277.4981327148.

The spelling of 21368803 in words is "twenty-one million, three hundred sixty-eight thousand, eight hundred three".