28242188882221 has 2 divisors, whose sum is σ = 28242188882222. Its totient is φ = 28242188882220.

The previous prime is 28242188882203. The next prime is 28242188882231. The reversal of 28242188882221 is 12228888124282.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19381213808100 + 8860975074121 = 4402410^2 + 2976739^2 .

It is a cyclic number.

It is not a de Polignac number, because 28242188882221 - 2⁵ = 28242188882189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28242188882231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14121094441110 + 14121094441111.

It is an arithmetic number, because the mean of its divisors is an integer number (14121094441111).

Almost surely, 2^{28242188882221} is an apocalyptic number.

It is an amenable number.

28242188882221 is a deficient number, since it is larger than the sum of its proper divisors (1).

28242188882221 is an equidigital number, since it uses as much as digits as its factorization.

28242188882221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8388608, while the sum is 58.

The spelling of 28242188882221 in words is "twenty-eight trillion, two hundred forty-two billion, one hundred eighty-eight million, eight hundred eighty-two thousand, two hundred twenty-one".