171138909 has 16 divisors (see below), whose sum is σ = 240889280. Its totient is φ = 108074736.

The previous prime is 171138907. The next prime is 171138911. The reversal of 171138909 is 909831171.

It is an interprime number because it is at equal distance from previous prime (171138907) and next prime (171138911).

It is not a de Polignac number, because 171138909 - 2¹ = 171138907 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171138907) 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 in 15 ways as a sum of consecutive naturals, for example, 16419 + ... + 24735.

It is an arithmetic number, because the mean of its divisors is an integer number (15055580).

Almost surely, 2^171138909 is an apocalyptic number.

171138909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

171138909 is a deficient number, since it is larger than the sum of its proper divisors (69750371).

171138909 is an frugal number, since it uses more digits than its factorization.

171138909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8377 (or 8339 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 39.

The square root of 171138909 is about 13082.0070707824. The cubic root of 171138909 is about 555.2001647942.

The spelling of 171138909 in words is "one hundred seventy-one million, one hundred thirty-eight thousand, nine hundred nine".