21222222212 has 24 divisors (see below), whose sum is σ = 37893336600. Its totient is φ = 10397721600.

The previous prime is 21222222209. The next prime is 21222222223.

21222222212 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 13559670916 + 7662551296 = 116446^2 + 87536^2 .

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

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, 231587 + ... + 309962.

It is an arithmetic number, because the mean of its divisors is an integer number (1578889025).

Almost surely, 2^21222222212 is an apocalyptic number.

It is an amenable number.

21222222212 is a deficient number, since it is larger than the sum of its proper divisors (16671114388).

21222222212 is a wasteful number, since it uses less digits than its factorization.

21222222212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541751 (or 541749 counting only the distinct ones).

The product of its digits is 512, while the sum is 20.

The spelling of 21222222212 in words is "twenty-one billion, two hundred twenty-two million, two hundred twenty-two thousand, two hundred twelve".