21200021116 has 12 divisors (see below), whose sum is σ = 37150245160. Its totient is φ = 10585665360.

The previous prime is 21200021111. The next prime is 21200021149. The reversal of 21200021116 is 61112000212.

It is a self number, because there is not a number n which added to its sum of digits gives 21200021116.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200021111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3582975 + ... + 3588886.

Almost surely, 2^21200021116 is an apocalyptic number.

It is an amenable number.

21200021116 is a deficient number, since it is larger than the sum of its proper divisors (15950224044).

21200021116 is a wasteful number, since it uses less digits than its factorization.

21200021116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7172604 (or 7172602 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21200021116 its reverse (61112000212), we get a palindrome (82312021328).

The spelling of 21200021116 in words is "twenty-one billion, two hundred million, twenty-one thousand, one hundred sixteen".