21122244 has 108 divisors (see below), whose sum is σ = 63371308. Its totient is φ = 5892480.

The previous prime is 21122221. The next prime is 21122251. The reversal of 21122244 is 44222112.

It can be written as a sum of positive squares in 2 ways, for example, as 6969600 + 14152644 = 2640^2 + 3762^2 .

It is a super-2 number, since 2×21122244² = 892298383191072, which 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 polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 56442 + ... + 56814.

Almost surely, 2^21122244 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21122244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31685654).

21122244 is an abundant number, since it is smaller than the sum of its proper divisors (42249064).

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

21122244 is a wasteful number, since it uses less digits than its factorization.

21122244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 418 (or 402 counting only the distinct ones).

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

The square root of 21122244 is about 4595.8942546582. The cubic root of 21122244 is about 276.4267186200.

Adding to 21122244 its reverse (44222112), we get a palindrome (65344356).

It can be divided in two parts, 2112 and 2244, that added together give a square (4356 = 66²).

The spelling of 21122244 in words is "twenty-one million, one hundred twenty-two thousand, two hundred forty-four".