21220043412 has 24 divisors (see below), whose sum is σ = 49903307776. Its totient is φ = 7017651648.

The previous prime is 21220043393. The next prime is 21220043423. The reversal of 21220043412 is 21434002212.

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, 6960433 + ... + 6963480.

Almost surely, 2^21220043412 is an apocalyptic number.

It is an amenable number.

21220043412 is an abundant number, since it is smaller than the sum of its proper divisors (28683264364).

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

21220043412 is a wasteful number, since it uses less digits than its factorization.

21220043412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13924047 (or 13924045 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21220043412 its reverse (21434002212), we get a palindrome (42654045624).

The spelling of 21220043412 in words is "twenty-one billion, two hundred twenty million, forty-three thousand, four hundred twelve".