21103203213 has 20 divisors (see below), whose sum is σ = 31544277468. Its totient is φ = 14059992960.

The previous prime is 21103203203. The next prime is 21103203217. The reversal of 21103203213 is 31230230112.

21103203213 is a `hidden beast` number, since 21 + 1 + 0 + 320 + 321 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17486624169 + 3616579044 = 132237^2 + 60138^2 .

It is not a de Polignac number, because 21103203213 - 2³⁴ = 3923334029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103203217) 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 19 ways as a sum of consecutive naturals, for example, 49893 + ... + 211413.

Almost surely, 2^21103203213 is an apocalyptic number.

It is an amenable number.

21103203213 is a deficient number, since it is larger than the sum of its proper divisors (10441074255).

21103203213 is a wasteful number, since it uses less digits than its factorization.

21103203213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163146 (or 163137 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21103203213 its reverse (31230230112), we get a palindrome (52333433325).

The spelling of 21103203213 in words is "twenty-one billion, one hundred three million, two hundred three thousand, two hundred thirteen".