170555221 has 2 divisors, whose sum is σ = 170555222. Its totient is φ = 170555220.

The previous prime is 170555183. The next prime is 170555249. The reversal of 170555221 is 122555071.

It is an a-pointer prime, because the next prime (170555249) can be obtained adding 170555221 to its sum of digits (28).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167702500 + 2852721 = 12950^2 + 1689^2 .

It is an emirp because it is prime and its reverse (122555071) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 170555221 - 2¹⁹ = 170030933 is a prime.

It is equal to p_9532432 and since 170555221 and 9532432 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 170555221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (170555251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85277610 + 85277611.

It is an arithmetic number, because the mean of its divisors is an integer number (85277611).

Almost surely, 2^170555221 is an apocalyptic number.

It is an amenable number.

170555221 is a deficient number, since it is larger than the sum of its proper divisors (1).

170555221 is an equidigital number, since it uses as much as digits as its factorization.

170555221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3500, while the sum is 28.

The square root of 170555221 is about 13059.6792073925. The cubic root of 170555221 is about 554.5682555193.

The spelling of 170555221 in words is "one hundred seventy million, five hundred fifty-five thousand, two hundred twenty-one".