22721166 has 48 divisors (see below), whose sum is σ = 53660880. Its totient is φ = 6906240.

The previous prime is 22721161. The next prime is 22721191. The reversal of 22721166 is 66112722.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22721161) 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 23 ways as a sum of consecutive naturals, for example, 20281 + ... + 21371.

It is an arithmetic number, because the mean of its divisors is an integer number (1117935).

Almost surely, 2^22721166 is an apocalyptic number.

22721166 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 22721166, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26830440).

22721166 is an abundant number, since it is smaller than the sum of its proper divisors (30939714).

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

22721166 is a wasteful number, since it uses less digits than its factorization.

22721166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1201 (or 1198 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 22721166 is about 4766.6724242389. The cubic root of 22721166 is about 283.2327950865.

Adding to 22721166 its reverse (66112722), we get a palindrome (88833888).

The spelling of 22721166 in words is "twenty-two million, seven hundred twenty-one thousand, one hundred sixty-six".