171087981 has 8 divisors (see below), whose sum is σ = 231857184. Its totient is φ = 112188720.

The previous prime is 171087979. The next prime is 171088019. The reversal of 171087981 is 189780171.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 171087981 - 2¹ = 171087979 is a prime.

It is a super-2 number, since 2×171087981² = 58542194485312722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171087901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 467271 + ... + 467636.

It is an arithmetic number, because the mean of its divisors is an integer number (28982148).

Almost surely, 2^171087981 is an apocalyptic number.

It is an amenable number.

171087981 is a deficient number, since it is larger than the sum of its proper divisors (60769203).

171087981 is an equidigital number, since it uses as much as digits as its factorization.

171087981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934971.

The product of its (nonzero) digits is 28224, while the sum is 42.

The square root of 171087981 is about 13080.0604356402. The cubic root of 171087981 is about 555.1450866526.

The spelling of 171087981 in words is "one hundred seventy-one million, eighty-seven thousand, nine hundred eighty-one".