171520417 has 2 divisors, whose sum is σ = 171520418. Its totient is φ = 171520416.

The previous prime is 171520411. The next prime is 171520457. The reversal of 171520417 is 714025171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149842081 + 21678336 = 12241^2 + 4656^2 .

It is an emirp because it is prime and its reverse (714025171) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 171520417 - 2³ = 171520409 is a prime.

It is not a weakly prime, because it can be changed into another prime (171520411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85760208 + 85760209.

It is an arithmetic number, because the mean of its divisors is an integer number (85760209).

Almost surely, 2^171520417 is an apocalyptic number.

It is an amenable number.

171520417 is a deficient number, since it is larger than the sum of its proper divisors (1).

171520417 is an equidigital number, since it uses as much as digits as its factorization.

171520417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1960, while the sum is 28.

The square root of 171520417 is about 13096.5803551920. The cubic root of 171520417 is about 555.6124149108.

Adding to 171520417 its reverse (714025171), we get a palindrome (885545588).

The spelling of 171520417 in words is "one hundred seventy-one million, five hundred twenty thousand, four hundred seventeen".