171580121856 has 864 divisors, whose sum is σ = 616255861760. Its totient is φ = 46750556160.

The previous prime is 171580121837. The next prime is 171580121879. The reversal of 171580121856 is 658121085171.

171580121856 is a `hidden beast` number, since 1 + 7 + 1 + 580 + 1 + 2 + 18 + 56 = 666.

171580121856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×171580121856² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 467520585 + ... + 467520951.

Almost surely, 2^171580121856 is an apocalyptic number.

171580121856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 171580121856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308127930880).

171580121856 is an abundant number, since it is smaller than the sum of its proper divisors (444675739904).

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

171580121856 is a wasteful number, since it uses less digits than its factorization.

171580121856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 470 (or 439 counting only the distinct ones).

The product of its (nonzero) digits is 134400, while the sum is 45.

The spelling of 171580121856 in words is "one hundred seventy-one billion, five hundred eighty million, one hundred twenty-one thousand, eight hundred fifty-six".