21222212012 has 6 divisors (see below), whose sum is σ = 37138871028. Its totient is φ = 10611106004.

The previous prime is 21222211999. The next prime is 21222212029. The reversal of 21222212012 is 21021222212.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652776498 + ... + 2652776505.

It is an arithmetic number, because the mean of its divisors is an integer number (6189811838).

Almost surely, 2^21222212012 is an apocalyptic number.

It is an amenable number.

21222212012 is a deficient number, since it is larger than the sum of its proper divisors (15916659016).

21222212012 is a wasteful number, since it uses less digits than its factorization.

21222212012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5305553007 (or 5305553005 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21222212012 its reverse (21021222212), we get a palindrome (42243434224).

The spelling of 21222212012 in words is "twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, twelve".