171213109 has 2 divisors, whose sum is σ = 171213110. Its totient is φ = 171213108.

The previous prime is 171213101. The next prime is 171213131. The reversal of 171213109 is 901312171.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131560900 + 39652209 = 11470^2 + 6297^2 .

It is a cyclic number.

It is not a de Polignac number, because 171213109 - 2³ = 171213101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171213101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85606554 + 85606555.

It is an arithmetic number, because the mean of its divisors is an integer number (85606555).

Almost surely, 2^171213109 is an apocalyptic number.

It is an amenable number.

171213109 is a deficient number, since it is larger than the sum of its proper divisors (1).

171213109 is an equidigital number, since it uses as much as digits as its factorization.

171213109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 25.

The square root of 171213109 is about 13084.8427197273. The cubic root of 171213109 is about 555.2803918257.

The spelling of 171213109 in words is "one hundred seventy-one million, two hundred thirteen thousand, one hundred nine".