171987156 has 36 divisors (see below), whose sum is σ = 474268704. Its totient is φ = 52117200.

The previous prime is 171987133. The next prime is 171987157. The reversal of 171987156 is 651789171.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171987157) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 216760 + ... + 217551.

Almost surely, 2^171987156 is an apocalyptic number.

It is an amenable number.

171987156 is an abundant number, since it is smaller than the sum of its proper divisors (302281548).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

171987156 is a wasteful number, since it uses less digits than its factorization.

171987156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434332 (or 434327 counting only the distinct ones).

The product of its digits is 105840, while the sum is 45.

The square root of 171987156 is about 13114.3873665528. The cubic root of 171987156 is about 556.1159334183.

The spelling of 171987156 in words is "one hundred seventy-one million, nine hundred eighty-seven thousand, one hundred fifty-six".