21011222212 has 12 divisors (see below), whose sum is σ = 36797780880. Its totient is φ = 10497570536.

The previous prime is 21011222201. The next prime is 21011222213. The reversal of 21011222212 is 21222211012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21011222213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2004262 + ... + 2014717.

It is an arithmetic number, because the mean of its divisors is an integer number (3066481740).

Almost surely, 2^21011222212 is an apocalyptic number.

It is an amenable number.

21011222212 is a deficient number, since it is larger than the sum of its proper divisors (15786558668).

21011222212 is a wasteful number, since it uses less digits than its factorization.

21011222212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4020290 (or 4020288 counting only the distinct ones).

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

Adding to 21011222212 its reverse (21222211012), we get a palindrome (42233433224).

It can be divided in two parts, 210112 and 22212, that added together give a square (232324 = 482²).

The spelling of 21011222212 in words is "twenty-one billion, eleven million, two hundred twenty-two thousand, two hundred twelve".