22242721 has 2 divisors, whose sum is σ = 22242722. Its totient is φ = 22242720.

The previous prime is 22242713. The next prime is 22242757. The reversal of 22242721 is 12724222.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 1440000 = 4561^2 + 1200^2 .

It is a cyclic number.

It is not a de Polignac number, because 22242721 - 2³ = 22242713 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 22242692 and 22242701.

It is not a weakly prime, because it can be changed into another prime (22242761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11121360 + 11121361.

It is an arithmetic number, because the mean of its divisors is an integer number (11121361).

Almost surely, 2^22242721 is an apocalyptic number.

It is an amenable number.

22242721 is a deficient number, since it is larger than the sum of its proper divisors (1).

22242721 is an equidigital number, since it uses as much as digits as its factorization.

22242721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 896, while the sum is 22.

The square root of 22242721 is about 4716.2189304569. The cubic root of 22242721 is about 281.2306418940.

Adding to 22242721 its reverse (12724222), we get a palindrome (34966943).

The spelling of 22242721 in words is "twenty-two million, two hundred forty-two thousand, seven hundred twenty-one".