21011305203 has 48 divisors (see below), whose sum is σ = 36823824000. Its totient is φ = 11802916944.

The previous prime is 21011305201. The next prime is 21011305241. The reversal of 21011305203 is 30250311012.

21011305203 is a `hidden beast` number, since 2 + 10 + 1 + 130 + 520 + 3 = 666.

It is not a de Polignac number, because 21011305203 - 2¹ = 21011305201 is a prime.

It is a super-2 number, since 2×21011305203² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21011305201) 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 47 ways as a sum of consecutive naturals, for example, 56533 + ... + 212646.

It is an arithmetic number, because the mean of its divisors is an integer number (767163000).

Almost surely, 2^21011305203 is an apocalyptic number.

21011305203 is a deficient number, since it is larger than the sum of its proper divisors (15812518797).

21011305203 is a wasteful number, since it uses less digits than its factorization.

21011305203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269261 (or 269248 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

Adding to 21011305203 its reverse (30250311012), we get a palindrome (51261616215).

The spelling of 21011305203 in words is "twenty-one billion, eleven million, three hundred five thousand, two hundred three".