21408500903 has 2 divisors, whose sum is σ = 21408500904. Its totient is φ = 21408500902.

The previous prime is 21408500863. The next prime is 21408500923. The reversal of 21408500903 is 30900580412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21408500903 - 2³⁰ = 20334759079 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21408500903.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21408500923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10704250451 + 10704250452.

It is an arithmetic number, because the mean of its divisors is an integer number (10704250452).

Almost surely, 2^21408500903 is an apocalyptic number.

21408500903 is a deficient number, since it is larger than the sum of its proper divisors (1).

21408500903 is an equidigital number, since it uses as much as digits as its factorization.

21408500903 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The spelling of 21408500903 in words is "twenty-one billion, four hundred eight million, five hundred thousand, nine hundred three".