22204721 has 16 divisors (see below), whose sum is σ = 28211328. Its totient is φ = 16972800.

The previous prime is 22204697. The next prime is 22204751. The reversal of 22204721 is 12740222.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 22204721 - 2¹⁸ = 21942577 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22204693 and 22204702.

It is not an unprimeable number, because it can be changed into a prime (22204751) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 1361 + ... + 6801.

It is an arithmetic number, because the mean of its divisors is an integer number (1763208).

Almost surely, 2^22204721 is an apocalyptic number.

It is an amenable number.

22204721 is a deficient number, since it is larger than the sum of its proper divisors (6006607).

22204721 is a wasteful number, since it uses less digits than its factorization.

22204721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5512.

The product of its (nonzero) digits is 448, while the sum is 20.

The square root of 22204721 is about 4712.1885573478. The cubic root of 22204721 is about 281.0703968709.

Adding to 22204721 its reverse (12740222), we get a palindrome (34944943).

The spelling of 22204721 in words is "twenty-two million, two hundred four thousand, seven hundred twenty-one".