171255421 has 2 divisors, whose sum is σ = 171255422. Its totient is φ = 171255420.

The previous prime is 171255389. The next prime is 171255431. The reversal of 171255421 is 124552171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154032921 + 17222500 = 12411^2 + 4150^2 .

It is a cyclic number.

It is not a de Polignac number, because 171255421 - 2⁵ = 171255389 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 171255421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171255431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85627710 + 85627711.

It is an arithmetic number, because the mean of its divisors is an integer number (85627711).

Almost surely, 2^171255421 is an apocalyptic number.

It is an amenable number.

171255421 is a deficient number, since it is larger than the sum of its proper divisors (1).

171255421 is an equidigital number, since it uses as much as digits as its factorization.

171255421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2800, while the sum is 28.

The square root of 171255421 is about 13086.4594524264. The cubic root of 171255421 is about 555.3261303187.

The spelling of 171255421 in words is "one hundred seventy-one million, two hundred fifty-five thousand, four hundred twenty-one".