21222112210 has 16 divisors (see below), whose sum is σ = 41138248536. Its totient is φ = 7835856768.

The previous prime is 21222112189. The next prime is 21222112229. The reversal of 21222112210 is 1221122212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18846622089 + 2375490121 = 137283^2 + 48739^2 .

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, 81623379 + ... + 81623638.

Almost surely, 2^21222112210 is an apocalyptic number.

21222112210 is a deficient number, since it is larger than the sum of its proper divisors (19916136326).

21222112210 is a wasteful number, since it uses less digits than its factorization.

21222112210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163247037.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21222112210 its reverse (1221122212), we get a palindrome (22443234422).

The spelling of 21222112210 in words is "twenty-one billion, two hundred twenty-two million, one hundred twelve thousand, two hundred ten".