171920591 has 2 divisors, whose sum is σ = 171920592. Its totient is φ = 171920590.

The previous prime is 171920533. The next prime is 171920629. The reversal of 171920591 is 195029171.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 171920591 - 2¹⁰ = 171919567 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171920291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85960295 + 85960296.

It is an arithmetic number, because the mean of its divisors is an integer number (85960296).

Almost surely, 2^171920591 is an apocalyptic number.

171920591 is a deficient number, since it is larger than the sum of its proper divisors (1).

171920591 is an equidigital number, since it uses as much as digits as its factorization.

171920591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 35.

The square root of 171920591 is about 13111.8492593532. The cubic root of 171920591 is about 556.0441787696.

The spelling of 171920591 in words is "one hundred seventy-one million, nine hundred twenty thousand, five hundred ninety-one".