21122211222 has 48 divisors (see below), whose sum is σ = 52319228832. Its totient is φ = 6033000960.

The previous prime is 21122211217. The next prime is 21122211241. The reversal of 21122211222 is 22211222112.

It is a happy number.

21122211222 is a `hidden beast` number, since 211 + 22 + 211 + 222 = 666.

It is a super-2 number, since 2×21122211222² (a number of 21 digits) contains 22 as substring.

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

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

It is a junction number, because it is equal to n+sod(n) for n = 21122211195 and 21122211204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 398548 + ... + 448424.

It is an arithmetic number, because the mean of its divisors is an integer number (1089983934).

Almost surely, 2^21122211222 is an apocalyptic number.

21122211222 is an abundant number, since it is smaller than the sum of its proper divisors (31197017610).

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

21122211222 is a wasteful number, since it uses less digits than its factorization.

21122211222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53253 (or 53250 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

Adding to 21122211222 its reverse (22211222112), we get a palindrome (43333433334).

It can be divided in two parts, 211222112 and 22, that multiplied together give a palindrome (4646886464).

The spelling of 21122211222 in words is "twenty-one billion, one hundred twenty-two million, two hundred eleven thousand, two hundred twenty-two".