28055884921 has 2 divisors, whose sum is σ = 28055884922. Its totient is φ = 28055884920.

The previous prime is 28055884867. The next prime is 28055884931. The reversal of 28055884921 is 12948855082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25836061696 + 2219823225 = 160736^2 + 47115^2 .

It is a cyclic number.

It is not a de Polignac number, because 28055884921 - 2²⁵ = 28022330489 is a prime.

It is not a weakly prime, because it can be changed into another prime (28055884931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14027942460 + 14027942461.

It is an arithmetic number, because the mean of its divisors is an integer number (14027942461).

Almost surely, 2^28055884921 is an apocalyptic number.

It is an amenable number.

28055884921 is a deficient number, since it is larger than the sum of its proper divisors (1).

28055884921 is an equidigital number, since it uses as much as digits as its factorization.

28055884921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1843200, while the sum is 52.

The spelling of 28055884921 in words is "twenty-eight billion, fifty-five million, eight hundred eighty-four thousand, nine hundred twenty-one".