21344424212 has 72 divisors (see below), whose sum is σ = 42522160800. Its totient is φ = 9336938688.

The previous prime is 21344424163. The next prime is 21344424217. The reversal of 21344424212 is 21242444312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21344424217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1156763 + ... + 1175069.

Almost surely, 2^21344424212 is an apocalyptic number.

It is an amenable number.

21344424212 is a deficient number, since it is larger than the sum of its proper divisors (21177736588).

21344424212 is a wasteful number, since it uses less digits than its factorization.

21344424212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18405 (or 18380 counting only the distinct ones).

The product of its digits is 12288, while the sum is 29.

Adding to 21344424212 its reverse (21242444312), we get a palindrome (42586868524).

The spelling of 21344424212 in words is "twenty-one billion, three hundred forty-four million, four hundred twenty-four thousand, two hundred twelve".