171020321 has 2 divisors, whose sum is σ = 171020322. Its totient is φ = 171020320.

The previous prime is 171020309. The next prime is 171020407. The reversal of 171020321 is 123020171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166693921 + 4326400 = 12911^2 + 2080^2 .

It is an emirp because it is prime and its reverse (123020171) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171020321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 171020321.

It is not a weakly prime, because it can be changed into another prime (171028321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85510160 + 85510161.

It is an arithmetic number, because the mean of its divisors is an integer number (85510161).

Almost surely, 2^171020321 is an apocalyptic number.

It is an amenable number.

171020321 is a deficient number, since it is larger than the sum of its proper divisors (1).

171020321 is an equidigital number, since it uses as much as digits as its factorization.

171020321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 171020321 is about 13077.4738003943. The cubic root of 171020321 is about 555.0718961049.

Adding to 171020321 its reverse (123020171), we get a palindrome (294040492).

The spelling of 171020321 in words is "one hundred seventy-one million, twenty thousand, three hundred twenty-one".