21124221212 has 12 divisors (see below), whose sum is σ = 36991863216. Its totient is φ = 10555117440.

The previous prime is 21124221179. The next prime is 21124221271. The reversal of 21124221212 is 21212242112.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1741493 + ... + 1753580.

It is an arithmetic number, because the mean of its divisors is an integer number (3082655268).

Almost surely, 2^21124221212 is an apocalyptic number.

It is an amenable number.

21124221212 is a deficient number, since it is larger than the sum of its proper divisors (15867642004).

21124221212 is a wasteful number, since it uses less digits than its factorization.

21124221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3496588 (or 3496586 counting only the distinct ones).

The product of its digits is 256, while the sum is 20.

Adding to 21124221212 its reverse (21212242112), we get a palindrome (42336463324).

The spelling of 21124221212 in words is "twenty-one billion, one hundred twenty-four million, two hundred twenty-one thousand, two hundred twelve".