21203120303 has 4 divisors (see below), whose sum is σ = 21696216168. Its totient is φ = 20710024440.

The previous prime is 21203120299. The next prime is 21203120347. The reversal of 21203120303 is 30302130212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21203120303 - 2² = 21203120299 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203120363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246547868 + ... + 246547953.

It is an arithmetic number, because the mean of its divisors is an integer number (5424054042).

Almost surely, 2^21203120303 is an apocalyptic number.

21203120303 is a deficient number, since it is larger than the sum of its proper divisors (493095865).

21203120303 is an equidigital number, since it uses as much as digits as its factorization.

21203120303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493095864.

The product of its (nonzero) digits is 216, while the sum is 17.

Adding to 21203120303 its reverse (30302130212), we get a palindrome (51505250515).

Subtracting 21203120303 from its reverse (30302130212), we obtain a palindrome (9099009909).

The spelling of 21203120303 in words is "twenty-one billion, two hundred three million, one hundred twenty thousand, three hundred three".