22781228 has 24 divisors (see below), whose sum is σ = 42947520. Its totient is φ = 10538640.

The previous prime is 22781221. The next prime is 22781261. The reversal of 22781228 is 82218722.

It is a junction number, because it is equal to n+sod(n) for n = 22781194 and 22781203.

It is not an unprimeable number, because it can be changed into a prime (22781221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218 + ... + 6753.

It is an arithmetic number, because the mean of its divisors is an integer number (1789480).

Almost surely, 2^22781228 is an apocalyptic number.

It is an amenable number.

22781228 is a deficient number, since it is larger than the sum of its proper divisors (20166292).

22781228 is a wasteful number, since it uses less digits than its factorization.

22781228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7037 (or 7035 counting only the distinct ones).

The product of its digits is 7168, while the sum is 32.

The square root of 22781228 is about 4772.9684683643. The cubic root of 22781228 is about 283.4821449728.

It can be divided in two parts, 227812 and 28, that multiplied together give a palindrome (6378736).

The spelling of 22781228 in words is "twenty-two million, seven hundred eighty-one thousand, two hundred twenty-eight".