285305221 has 2 divisors, whose sum is σ = 285305222. Its totient is φ = 285305220.

The previous prime is 285305171. The next prime is 285305233. The reversal of 285305221 is 122503582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212868100 + 72437121 = 14590^2 + 8511^2 .

It is a cyclic number.

It is not a de Polignac number, because 285305221 - 2⁹ = 285304709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 285305221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285305021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142652610 + 142652611.

It is an arithmetic number, because the mean of its divisors is an integer number (142652611).

Almost surely, 2^285305221 is an apocalyptic number.

It is an amenable number.

285305221 is a deficient number, since it is larger than the sum of its proper divisors (1).

285305221 is an equidigital number, since it uses as much as digits as its factorization.

285305221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 285305221 is about 16890.9804629571. The cubic root of 285305221 is about 658.3192780777.

The spelling of 285305221 in words is "two hundred eighty-five million, three hundred five thousand, two hundred twenty-one".