21440803 has 2 divisors, whose sum is σ = 21440804. Its totient is φ = 21440802.

The previous prime is 21440801. The next prime is 21440821. The reversal of 21440803 is 30804412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21440803 - 2¹ = 21440801 is a prime.

Together with 21440801, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21440801) 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, 10720401 + 10720402.

It is an arithmetic number, because the mean of its divisors is an integer number (10720402).

Almost surely, 2^21440803 is an apocalyptic number.

21440803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21440803 is an equidigital number, since it uses as much as digits as its factorization.

21440803 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21440803 is about 4630.4214710974. The cubic root of 21440803 is about 277.8094505337.

The spelling of 21440803 in words is "twenty-one million, four hundred forty thousand, eight hundred three".