20244221 has 4 divisors (see below), whose sum is σ = 20295612. Its totient is φ = 20192832.

The previous prime is 20244199. The next prime is 20244239. The reversal of 20244221 is 12244202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12244202 = 2 ⋅6122101.

It can be written as a sum of positive squares in 2 ways, for example, as 5112121 + 15132100 = 2261^2 + 3890^2 .

It is a cyclic number.

It is not a de Polignac number, because 20244221 - 2⁶ = 20244157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20244221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20244121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25100 + ... + 25893.

It is an arithmetic number, because the mean of its divisors is an integer number (5073903).

Almost surely, 2^20244221 is an apocalyptic number.

It is an amenable number.

20244221 is a deficient number, since it is larger than the sum of its proper divisors (51391).

20244221 is an equidigital number, since it uses as much as digits as its factorization.

20244221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51390.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 20244221 is about 4499.3578430705. The cubic root of 20244221 is about 272.5421577174.

Adding to 20244221 its reverse (12244202), we get a palindrome (32488423).

The spelling of 20244221 in words is "twenty million, two hundred forty-four thousand, two hundred twenty-one".