170021 has 2 divisors, whose sum is σ = 170022. Its totient is φ = 170020.

The previous prime is 170003. The next prime is 170029. The reversal of 170021 is 120071.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 148996 + 21025 = 386^2 + 145^2 .

It is a cyclic number.

It is not a de Polignac number, because 170021 - 2⁶ = 169957 is a prime.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 169984 and 170011.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 170021.

It is not a weakly prime, because it can be changed into another prime (170029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85010 + 85011.

It is an arithmetic number, because the mean of its divisors is an integer number (85011).

2¹⁷⁰⁰²¹ is an apocalyptic number.

It is an amenable number.

170021 is a deficient number, since it is larger than the sum of its proper divisors (1).

170021 is an equidigital number, since it uses as much as digits as its factorization.

170021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14, while the sum is 11.

The square root of 170021 is about 412.3360280160. The cubic root of 170021 is about 55.3988635094.

Adding to 170021 its reverse (120071), we get a palindrome (290092).

The spelling of 170021 in words is "one hundred seventy thousand, twenty-one", and thus it is an iban number.