171256957987 has 8 divisors (see below), whose sum is σ = 173195824320. Its totient is φ = 169318416960.

The previous prime is 171256957981. The next prime is 171256958003. The reversal of 171256957987 is 789759652171.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171256957987 is a prime.

It is a super-2 number, since 2×171256957987² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171256957981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1069062 + ... + 1218772.

It is an arithmetic number, because the mean of its divisors is an integer number (21649478040).

Almost surely, 2^171256957987 is an apocalyptic number.

171256957987 is a deficient number, since it is larger than the sum of its proper divisors (1938866333).

171256957987 is a wasteful number, since it uses less digits than its factorization.

171256957987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162653.

The product of its digits is 66679200, while the sum is 67.

The spelling of 171256957987 in words is "one hundred seventy-one billion, two hundred fifty-six million, nine hundred fifty-seven thousand, nine hundred eighty-seven".