21220212222 has 32 divisors (see below), whose sum is σ = 51442940160. Its totient is φ = 6430367160.

The previous prime is 21220212217. The next prime is 21220212227. The reversal of 21220212222 is 22221202212.

21220212222 is a `hidden beast` number, since 212 + 20 + 212 + 222 = 666.

It is an interprime number because it is at equal distance from previous prime (21220212217) and next prime (21220212227).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21220212195 and 21220212204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220212227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17861538 + ... + 17862725.

It is an arithmetic number, because the mean of its divisors is an integer number (1607591880).

Almost surely, 2^21220212222 is an apocalyptic number.

21220212222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21220212222 is an abundant number, since it is smaller than the sum of its proper divisors (30222727938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21220212222 is a wasteful number, since it uses less digits than its factorization.

21220212222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35724285 (or 35724279 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21220212222 its reverse (22221202212), we get a palindrome (43441414434).

The spelling of 21220212222 in words is "twenty-one billion, two hundred twenty million, two hundred twelve thousand, two hundred twenty-two".