21122122212 has 36 divisors (see below), whose sum is σ = 53441069136. Its totient is φ = 7034240880.

The previous prime is 21122122193. The next prime is 21122122237. The reversal of 21122122212 is 21222122112.

It is a happy number.

21122122212 is a `hidden beast` number, since 211 + 221 + 22 + 212 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21122122212² (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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 229618 + ... + 308169.

Almost surely, 2^21122122212 is an apocalyptic number.

It is an amenable number.

21122122212 is an abundant number, since it is smaller than the sum of its proper divisors (32318946924).

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

21122122212 is a wasteful number, since it uses less digits than its factorization.

21122122212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538888 (or 538883 counting only the distinct ones).

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

Adding to 21122122212 its reverse (21222122112), we get a palindrome (42344244324).

The spelling of 21122122212 in words is "twenty-one billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred twelve".