22181645 has 12 divisors (see below), whose sum is σ = 28094940. Its totient is φ = 16809984.

The previous prime is 22181641. The next prime is 22181701. The reversal of 22181645 is 54618122.

It can be written as a sum of positive squares in 2 ways, for example, as 13169641 + 9012004 = 3629^2 + 3002^2 .

It is not a de Polignac number, because 22181645 - 2² = 22181641 is a prime.

It is a super-3 number, since 3×22181645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22181641) 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 11 ways as a sum of consecutive naturals, for example, 4340 + ... + 7949.

It is an arithmetic number, because the mean of its divisors is an integer number (2341245).

Almost surely, 2^22181645 is an apocalyptic number.

It is an amenable number.

22181645 is a deficient number, since it is larger than the sum of its proper divisors (5913295).

22181645 is a wasteful number, since it uses less digits than its factorization.

22181645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12332 (or 12313 counting only the distinct ones).

The product of its digits is 3840, while the sum is 29.

The square root of 22181645 is about 4709.7393770781. The cubic root of 22181645 is about 280.9729967339.

Adding to 22181645 its reverse (54618122), we get a palindrome (76799767).

The spelling of 22181645 in words is "twenty-two million, one hundred eighty-one thousand, six hundred forty-five".