22161656 has 32 divisors (see below), whose sum is σ = 45982080. Its totient is φ = 9928800.

The previous prime is 22161647. The next prime is 22161661. The reversal of 22161656 is 65616122.

It is a super-2 number, since 2×22161656² = 982277993324672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4475 + ... + 8021.

It is an arithmetic number, because the mean of its divisors is an integer number (1436940).

Almost surely, 2^22161656 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 22161656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22991040).

22161656 is an abundant number, since it is smaller than the sum of its proper divisors (23820424).

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

22161656 is a wasteful number, since it uses less digits than its factorization.

22161656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3635 (or 3631 counting only the distinct ones).

The product of its digits is 4320, while the sum is 29.

The square root of 22161656 is about 4707.6168068355. The cubic root of 22161656 is about 280.8885717188. Note that the first 3 decimals are identical.

Adding to 22161656 its reverse (65616122), we get a palindrome (87777778).

The spelling of 22161656 in words is "twenty-two million, one hundred sixty-one thousand, six hundred fifty-six".