28141721 has 2 divisors, whose sum is σ = 28141722. Its totient is φ = 28141720.

The previous prime is 28141709. The next prime is 28141727. The reversal of 28141721 is 12714182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18156121 + 9985600 = 4261^2 + 3160^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28141721 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28141727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14070860 + 14070861.

It is an arithmetic number, because the mean of its divisors is an integer number (14070861).

Almost surely, 2^28141721 is an apocalyptic number.

It is an amenable number.

28141721 is a deficient number, since it is larger than the sum of its proper divisors (1).

28141721 is an equidigital number, since it uses as much as digits as its factorization.

28141721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 896, while the sum is 26.

The square root of 28141721 is about 5304.8770956545. The cubic root of 28141721 is about 304.1703548019.

The spelling of 28141721 in words is "twenty-eight million, one hundred forty-one thousand, seven hundred twenty-one".