21221096 has 32 divisors (see below), whose sum is σ = 43273440. Its totient is φ = 9697728.

The previous prime is 21221077. The next prime is 21221099. The reversal of 21221096 is 69012212.

It is not an unprimeable number, because it can be changed into a prime (21221099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10175 + ... + 12081.

It is an arithmetic number, because the mean of its divisors is an integer number (1352295).

Almost surely, 2^21221096 is an apocalyptic number.

21221096 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221096, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21636720).

21221096 is an abundant number, since it is smaller than the sum of its proper divisors (22052344).

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

21221096 is a wasteful number, since it uses less digits than its factorization.

21221096 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2033 (or 2029 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21221096 is about 4606.6360828700. The cubic root of 21221096 is about 276.8572728894.

The spelling of 21221096 in words is "twenty-one million, two hundred twenty-one thousand, ninety-six".