21212113203 has 24 divisors (see below), whose sum is σ = 31251254112. Its totient is φ = 13859733888.

The previous prime is 21212113201. The next prime is 21212113213. The reversal of 21212113203 is 30231121212.

It is not a de Polignac number, because 21212113203 - 2¹ = 21212113201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212113201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 431250 + ... + 477912.

It is an arithmetic number, because the mean of its divisors is an integer number (1302135588).

Almost surely, 2^21212113203 is an apocalyptic number.

21212113203 is a deficient number, since it is larger than the sum of its proper divisors (10039140909).

21212113203 is a wasteful number, since it uses less digits than its factorization.

21212113203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47675 (or 47672 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21212113203 its reverse (30231121212), we get a palindrome (51443234415).

The spelling of 21212113203 in words is "twenty-one billion, two hundred twelve million, one hundred thirteen thousand, two hundred three".