28221041 has 4 divisors (see below), whose sum is σ = 28427172. Its totient is φ = 28014912.

The previous prime is 28220999. The next prime is 28221049. The reversal of 28221041 is 14012282.

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: 14012282 = 2 ⋅7006141.

It can be written as a sum of positive squares in 2 ways, for example, as 23726641 + 4494400 = 4871^2 + 2120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28221041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28221049) 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, 102860 + ... + 103133.

It is an arithmetic number, because the mean of its divisors is an integer number (7106793).

Almost surely, 2^28221041 is an apocalyptic number.

It is an amenable number.

28221041 is a deficient number, since it is larger than the sum of its proper divisors (206131).

28221041 is a wasteful number, since it uses less digits than its factorization.

28221041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206130.

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 28221041 is about 5312.3479742954. The cubic root of 28221041 is about 304.4558639945.

The spelling of 28221041 in words is "twenty-eight million, two hundred twenty-one thousand, forty-one".