171561389 has 2 divisors, whose sum is σ = 171561390. Its totient is φ = 171561388.

The previous prime is 171561353. The next prime is 171561407. The reversal of 171561389 is 983165171.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 169260100 + 2301289 = 13010^2 + 1517^2 .

It is a cyclic number.

It is not a de Polignac number, because 171561389 - 2²⁰ = 170512813 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171561319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85780694 + 85780695.

It is an arithmetic number, because the mean of its divisors is an integer number (85780695).

Almost surely, 2^171561389 is an apocalyptic number.

It is an amenable number.

171561389 is a deficient number, since it is larger than the sum of its proper divisors (1).

171561389 is an equidigital number, since it uses as much as digits as its factorization.

171561389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 41.

The square root of 171561389 is about 13098.1444869111. The cubic root of 171561389 is about 555.6566520923.

The spelling of 171561389 in words is "one hundred seventy-one million, five hundred sixty-one thousand, three hundred eighty-nine".