21221002222 has 24 divisors (see below), whose sum is σ = 37135253304. Its totient is φ = 9068491152.

The previous prime is 21221002217. The next prime is 21221002223. The reversal of 21221002222 is 22220012212.

It is a super-2 number, since 2×21221002222² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21221002196 and 21221002205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221002223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 278013 + ... + 346024.

It is an arithmetic number, because the mean of its divisors is an integer number (1547302221).

Almost surely, 2^21221002222 is an apocalyptic number.

21221002222 is a deficient number, since it is larger than the sum of its proper divisors (15914251082).

21221002222 is a wasteful number, since it uses less digits than its factorization.

21221002222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624400 (or 624393 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21221002222 its reverse (22220012212), we get a palindrome (43441014434).

The spelling of 21221002222 in words is "twenty-one billion, two hundred twenty-one million, two thousand, two hundred twenty-two".