85857221 has 2 divisors, whose sum is σ = 85857222. Its totient is φ = 85857220.

The previous prime is 85857209. The next prime is 85857253. The reversal of 85857221 is 12275858.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 62188996 + 23668225 = 7886^2 + 4865^2 .

It is a cyclic number.

It is not a de Polignac number, because 85857221 - 2¹⁸ = 85595077 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85857521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42928610 + 42928611.

It is an arithmetic number, because the mean of its divisors is an integer number (42928611).

Almost surely, 2^85857221 is an apocalyptic number.

It is an amenable number.

85857221 is a deficient number, since it is larger than the sum of its proper divisors (1).

85857221 is an equidigital number, since it uses as much as digits as its factorization.

85857221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44800, while the sum is 38.

The square root of 85857221 is about 9265.9171699298. The cubic root of 85857221 is about 441.1560868222.

The spelling of 85857221 in words is "eighty-five million, eight hundred fifty-seven thousand, two hundred twenty-one".