171382987557 has 24 divisors (see below), whose sum is σ = 250467360000. Its totient is φ = 112918040928.

The previous prime is 171382987549. The next prime is 171382987627. The reversal of 171382987557 is 755789283171.

171382987557 is a `hidden beast` number, since 1 + 71 + 3 + 8 + 2 + 9 + 8 + 7 + 557 = 666.

It is not a de Polignac number, because 171382987557 - 2³ = 171382987549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 171382987494 and 171382987503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171382987507) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 54253 + ... + 587970.

It is an arithmetic number, because the mean of its divisors is an integer number (10436140000).

Almost surely, 2^171382987557 is an apocalyptic number.

It is an amenable number.

171382987557 is a deficient number, since it is larger than the sum of its proper divisors (79084372443).

171382987557 is a wasteful number, since it uses less digits than its factorization.

171382987557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642577 (or 642574 counting only the distinct ones).

The product of its digits is 29635200, while the sum is 63.

The spelling of 171382987557 in words is "one hundred seventy-one billion, three hundred eighty-two million, nine hundred eighty-seven thousand, five hundred fifty-seven".