170209121 has 2 divisors, whose sum is σ = 170209122. Its totient is φ = 170209120.

The previous prime is 170209111. The next prime is 170209147. The reversal of 170209121 is 121902071.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 170015521 + 193600 = 13039^2 + 440^2 .

It is an emirp because it is prime and its reverse (121902071) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 170209121 - 2⁶ = 170209057 is a prime.

It is a super-2 number, since 2×170209121² = 57942289743185282, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (170209111) 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, 85104560 + 85104561.

It is an arithmetic number, because the mean of its divisors is an integer number (85104561).

Almost surely, 2^170209121 is an apocalyptic number.

It is an amenable number.

170209121 is a deficient number, since it is larger than the sum of its proper divisors (1).

170209121 is an equidigital number, since it uses as much as digits as its factorization.

170209121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 170209121 is about 13046.4217699720. The cubic root of 170209121 is about 554.1928813976.

The spelling of 170209121 in words is "one hundred seventy million, two hundred nine thousand, one hundred twenty-one".