21122222112 has 72 divisors (see below), whose sum is σ = 60661118700. Its totient is φ = 6971020800.

The previous prime is 21122222111. The next prime is 21122222131.

It is a happy number.

21122222112 is a `hidden beast` number, since 211 + 222 + 221 + 12 = 666.

21122222112 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 17005203216 + 4117018896 = 130404^2 + 64164^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21122222112² (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 not an unprimeable number, because it can be changed into a prime (21122222111) 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, 333987 + ... + 392162.

Almost surely, 2^21122222112 is an apocalyptic number.

It is an amenable number.

21122222112 is an abundant number, since it is smaller than the sum of its proper divisors (39538896588).

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

21122222112 is a wasteful number, since it uses less digits than its factorization.

21122222112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726266 (or 726255 counting only the distinct ones).

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

The spelling of 21122222112 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty-two thousand, one hundred twelve".