21312203203 has 2 divisors, whose sum is σ = 21312203204. Its totient is φ = 21312203202.

The previous prime is 21312203177. The next prime is 21312203287. The reversal of 21312203203 is 30230221312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21312203203 is a prime.

It is not a weakly prime, because it can be changed into another prime (21312203303) 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, 10656101601 + 10656101602.

It is an arithmetic number, because the mean of its divisors is an integer number (10656101602).

Almost surely, 2^21312203203 is an apocalyptic number.

21312203203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21312203203 is an equidigital number, since it uses as much as digits as its factorization.

21312203203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21312203203 its reverse (30230221312), we get a palindrome (51542424515).

The spelling of 21312203203 in words is "twenty-one billion, three hundred twelve million, two hundred three thousand, two hundred three".