28327550221 has 2 divisors, whose sum is σ = 28327550222. Its totient is φ = 28327550220.

The previous prime is 28327550213. The next prime is 28327550249. The reversal of 28327550221 is 12205572382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16605157321 + 11722392900 = 128861^2 + 108270^2 .

It is a cyclic number.

It is not a de Polignac number, because 28327550221 - 2³ = 28327550213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28327550261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14163775110 + 14163775111.

It is an arithmetic number, because the mean of its divisors is an integer number (14163775111).

Almost surely, 2^28327550221 is an apocalyptic number.

It is an amenable number.

28327550221 is a deficient number, since it is larger than the sum of its proper divisors (1).

28327550221 is an equidigital number, since it uses as much as digits as its factorization.

28327550221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 67200, while the sum is 37.

The spelling of 28327550221 in words is "twenty-eight billion, three hundred twenty-seven million, five hundred fifty thousand, two hundred twenty-one".