21215030205 has 16 divisors (see below), whose sum is σ = 33974463744. Its totient is φ = 11304544320.

The previous prime is 21215030171. The next prime is 21215030209. The reversal of 21215030205 is 50203051212.

It is not a de Polignac number, because 21215030205 - 2⁸ = 21215029949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21215030209) 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, 616341 + ... + 649850.

It is an arithmetic number, because the mean of its divisors is an integer number (2123403984).

Almost surely, 2^21215030205 is an apocalyptic number.

It is an amenable number.

21215030205 is a deficient number, since it is larger than the sum of its proper divisors (12759433539).

21215030205 is a wasteful number, since it uses less digits than its factorization.

21215030205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1267316.

The product of its (nonzero) digits is 600, while the sum is 21.

Adding to 21215030205 its reverse (50203051212), we get a palindrome (71418081417).

The spelling of 21215030205 in words is "twenty-one billion, two hundred fifteen million, thirty thousand, two hundred five".