85505221 has 2 divisors, whose sum is σ = 85505222. Its totient is φ = 85505220.

The previous prime is 85505207. The next prime is 85505227. The reversal of 85505221 is 12250558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77176225 + 8328996 = 8785^2 + 2886^2 .

It is a cyclic number.

It is not a de Polignac number, because 85505221 - 2⁷ = 85505093 is a prime.

It is a super-2 number, since 2×85505221² = 14622285636517682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 85505221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85505227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42752610 + 42752611.

It is an arithmetic number, because the mean of its divisors is an integer number (42752611).

Almost surely, 2^85505221 is an apocalyptic number.

It is an amenable number.

85505221 is a deficient number, since it is larger than the sum of its proper divisors (1).

85505221 is an equidigital number, since it uses as much as digits as its factorization.

85505221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4000, while the sum is 28.

The square root of 85505221 is about 9246.9033194903. The cubic root of 85505221 is about 440.5523727253.

Adding to 85505221 its reverse (12250558), we get a palindrome (97755779).

The spelling of 85505221 in words is "eighty-five million, five hundred five thousand, two hundred twenty-one".