21100000203 has 16 divisors (see below), whose sum is σ = 31279372800. Its totient is φ = 14057615880.

The previous prime is 21100000157. The next prime is 21100000219. The reversal of 21100000203 is 30200000112.

It is a happy number.

It is not a de Polignac number, because 21100000203 - 2²⁹ = 20563129291 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21100000703) 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 in 15 ways as a sum of consecutive naturals, for example, 208543 + ... + 292728.

It is an arithmetic number, because the mean of its divisors is an integer number (1954960800).

Almost surely, 2^21100000203 is an apocalyptic number.

21100000203 is a deficient number, since it is larger than the sum of its proper divisors (10179372597).

21100000203 is a wasteful number, since it uses less digits than its factorization.

21100000203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 502839 (or 502833 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 21100000203 its reverse (30200000112), we get a palindrome (51300000315).

Subtracting 21100000203 from its reverse (30200000112), we obtain a palindrome (9099999909).

The spelling of 21100000203 in words is "twenty-one billion, one hundred million, two hundred three", and thus it is an aban number.