21545224212 has 24 divisors (see below), whose sum is σ = 50277939712. Its totient is φ = 7180920000.

The previous prime is 21545224201. The next prime is 21545224229. The reversal of 21545224212 is 21242254512.

It is a self number, because there is not a number n which added to its sum of digits gives 21545224212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11712 + ... + 207912.

Almost surely, 2^21545224212 is an apocalyptic number.

It is an amenable number.

21545224212 is an abundant number, since it is smaller than the sum of its proper divisors (28732715500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21545224212 is a wasteful number, since it uses less digits than its factorization.

21545224212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205359 (or 205357 counting only the distinct ones).

The product of its digits is 12800, while the sum is 30.

Adding to 21545224212 its reverse (21242254512), we get a palindrome (42787478724).

The spelling of 21545224212 in words is "twenty-one billion, five hundred forty-five million, two hundred twenty-four thousand, two hundred twelve".